The uncertainty of geological composition,the invisibility of the under-well real-time working conditions,and the complexity of the engineering simulation in the oil and gas field drilling and production process have hindered its scientific and efficient design and construction.The digital twin technology can bring up real-time,intelligent,and visualized project design and decision-making but has yet to lack a systematic method for modeling oil and gas field drilling and production.In this regard,the article first explored the current levels of investigation and implementation both domestically and abroad,based on that the level of development by applying the maturity index was quantified.It then proposed the digital twin modeling approach for drill-ing and production in the oil and gas field,which encompassed the modeling workflow,model division strategies,architecture for model assembly and integration,and modeling tools for constructing the digital twin.Also,two case were studied for drilling and production,using wellbore stability while drilling and offshore gas well production system as two examples,respectively.Finally,the difficulties and challenges related to the digital twin deployment in the field were analyzed,based on which the suggestions for its future development are proposed.It is found that the digital twin for drilling and production has stayed at the visualization level and at a relatively low degree of maturity compared to the manufacturing field on digital twin.The complex demand for oil and gas drilling and production systems can be divided into several clear and easy realized sub-demands.Based on requirement analysis,the modeled object can be separated to be various sub-models based on the granularity,dimension,and lifecycle.The sub-models are then assembled layer by layer across the model,function,and demand layers so that the multi-dimension and multi-field models can be integrated.Meanwhile,an improvement of their methods and an increase in efficiency for the model administration,data management,and engineering simulation ae desired.Moreover,the digital twin faces the problems such as difficulty in selection and fusion of multi-source heterogeneous data,vagueness in the sub-model definition,and ambiguity in the model validation,as well as the challenges such as the complicated kinetics processes,multi-division and multi-task collaboration,and development of domestic software tools.In summary,the digital twin modeling approach and the case studies in this article can provide a methodological guidance and practical reference for oil and gas drilling and production practices.

To address the challenges of the oil-based drilling fluid system's deteriorating rheological properties and insufficient plugging pressure resistance under high-low temperature cycling conditions in the Yaha gas storage reservoir drilling,a tempera-ture-sensitive high-temperature thickener,RHT,was developed.Optimized plugging materials and supporting agents were selected to construct a high-temperature resistant oil-based drilling fluid system.Characterization methods,including infrared spectroscopy,nuclear magnetic resonance hydrogen spectra,thermogravimetric analysis,and differential scanning calorimetry(DSC),were used to analyze RHT's molecular structure,thermal stability,and temperature-sensitive characteristics in depth.The systematic evaluation of its rheological control in emulsions and oil-based drilling fluids was conducted.Experimental results showed that RHT significantly improved the shear-thinning and thixotropic properties of the emulsion,demonstrating excellent rheological control capabilities under high-low temperature cycling conditions.At 80℃,the dynamic yield stress increased by 87%without any increase in plastic viscosity;at 220℃,the dynamic yield stress increased by 220%,with a dynamic plastic ratio of 0.49 Pa/(mPa·s).The drilling fluid system maintained strong rock-carrying capacity after aging at 220℃and effectively sealed 20～40 mesh sand beds and 1～3 mm cracks,achieving a maximum pressure resistance of 8 MPa.In the field application of the Yaha gas storage reservoir well X,this system significantly enhanced the rock-carrying and plugging performance of the drilling fluid,reducing complexities such as fluid loss and stuck pipe incidents,thereby providing strong technical support for the efficient development of the Yaha gas storage reservoir.

Low salinity water flooding is a new technology for enhancing oil recovery by adjusting the ion composition or con-centration of injected water.However,the applicable reservoir conditions and enhanced oil recovery mechanism of low salinity water flooding have not yet reached a consensus.In this paper,a series of laboratory experiments of wettability control-based low salinity flooding are carried out with plunger rock samples from marine carbonate reservoirs in the Middle East as the research object.Based on the theory of Derjaguin-Landau-Verwey-Overbeek theory(DLVO),an interfacial reaction model of a typical crude oil/brine/rock system is established,and the contact angle and total separation pressure are calculated simultaneously with the augmented Young-Laplace formula.The reliability of the model is verified by the literature experimental data,and the effects of ion concentration and ion type on the separation pressure curve and contact angle are clarified.The results show that in low salinity environments,the pore surface of carbonate rock is more water-wet under the action of fluid flushing,the oil displacement efficiency is higher,and the low salinity water improves the crude oil recovery by 3.2%;under the assumption of constant charge,the mathematical model established based on the DLVO theory for the crude oil/brine/rock system can accurately predict the change of contact angle;compared with the ion concentration,ion type has a greater impact on separation pressure and contact angle.Among divalent ions,Mg2+ions exhibit a more pronounced influence on wettability control compared to Ca2+ions.When the water film thickness is minimal,van der Waals force is the main force affecting the separation pressure.As the thickness of water film increases,the electric double layer force gradually becomes the main force.This study contributes to a deeper understanding of the wettability control mechanism of low salinity water flooding for enhanced oil recovery.

The fault-controlled fracture-cavity type oil and gas reservoir plays an important role in the exploration and develop-ment of oil and gas in the carbonate rocks of the Tarim Basin.Research shows that there are significant differences in the oil and gas development effects in different fractures or different segments of the same fracture in the Fuman Oilfield,leading to unclear oil and gas accumulation characteristics and affecting the efficient development of ultra-deep layers.This paper takes the strata from the Yijianfang Group to the Yingshan Group in the Fuman Oilfield of the Tarim Basin as an example,using drilling data,high-quality 3D seismic data,and production dynamic data to study the control effect of ultra-deep strike-slip faults on the degree of oil and gas accumulation.The results show that:(1)The oil and gas accumulation in the fault zone is mainly controlled by three factors:the contact relationship between the fault and the source rock,the fault's role as a migration pathway,and the size of the reservoir.(2)By comparing and analyzing the drilling production results,the paper establishes a quantitative relationship between the connectivity of the source,the fault's guiding role,the scale of the reservoir,and oil and gas accumulation,improving a set of evaluation and calculation methods for the differentiated accumulation degree of ultra-deep fault-controlled oil and gas reservoirs.(3)The source connectivity of deep and large faults is an important factor affecting the accumulation degree of fault-controlled oil and gas reservoirs.The higher the oil and gas accumulation,the better the contact between the fault and the source rock,the better the vertical connectivity of the migration pathway,and the larger the effective reservoir scale. This paper proposes a new understanding of the"source connectivity"analysis of fractures in fault-controlled fracture-cav-ity reservoirs and develops an evaluation technique for ultra-deep carbonate"fault-controlled oil and gas reservoir formation".Using this method,the oil and gas accumulation degree of the FI 19 fault zone in the Fuman Oilfield was analyzed,with a match rate of 92%to the well data.This method has good reference value for the further development practice of other oilfields in the Tarim Basin.

暂堵转向压裂是非常规油气资源开发过程中的重要增产改造手段之一.通过对国内外暂堵转向压裂技术文献的整理,从暂堵转向压裂机理、材料和工艺3个方面对暂堵转向压裂技术的发展进行了总结.首先,暂堵转向压裂过程包括3个关键步骤:暂堵剂运移、封堵、裂缝转向.不同暂堵剂颗粒的运移分异行为影响了其后续的封堵过程,进而影响新缝的开启,三者紧密相连.其次,在现场应用的暂堵剂种类繁多,包括固体颗粒、纤维、凝胶、泡沫等类型,需要根据储层特征优选适合的暂堵剂,特别是考虑其耐温性、降解性以及承压能力.目前,可降解颗粒和纤维暂堵剂是主流的发展趋势.最后,暂堵转向压裂技术具有广泛的应用场景,其效果得到多种监测手段的证实.在作业过程中需要根据暂堵剂类型的差异采用不同的加注方式,暂堵剂用量和加入时机可根据管外光纤、高频压力监测等多种先进技术手段进行优化设计.随着这些先进技术的应用与推广,暂堵转向压裂作业终将实现实时调控与优化.

In the process of fracturing in tight reservoirs,the imbibition and displacement of crude oil in reservoir pores by fracturing fluids has gradually become a key research field of enhanced oil recovery technology.However,the production characteristics and mechanism of pore crude oil at different scales in the process of imbibition are still unclear,which seriously restricts the optimal design of fracturing fluid system and the reasonable selection of mining technology.Taking the Chang 7 member tight reservoir in the Ordos Basin as the research object,the amphoteric surfactant(EAB-40)was used as the main agent of the clean fracturing fluid system,combined with T1-T2 two-dimensional nuclear magnetic resonance and wettability test,the influence of surfactant concentration on reservoir interface properties and fracturing fluid imbibition and displacement efficiency was systematically studied,and its microscopic mechanism was revealed.The experimental results show that EAB-40 signifi-cantly enhances the capillary driving force and crude oil desorption efficiency by synergistically reducing the oil-water interfacial tension(up to the order of 10-2 mN/m)and inducing the wettability reversal(the contact angle is reduced from 147° to 57.34°).The comprehensive oil displacement effect of the fracturing fluid system is optimal when the concentration of surfactant is 0.1 wt%.During the imbibibibition process,the wettability inversion is caused by the concentration of water-wet minerals in the small pores,and the diffusion of surfactants causes the wetting inversion,which drives the crude oil to migrate efficiently from the small pores T2<1 ms to the middle(T2 is between 1 and 100 ms)and large pores T2>100 ms.Polymer molecules improve the rheological properties of the fracturing fluid system and promote the deep utilization of residual oil in bound oil and blind end pores.Realize the triple synergistic imbibibibibition mechanism of"IFT reduction-wetting inversion-viscoelastic flow control".

西江30洼位于惠州凹陷西南部,由于前期深层地震资料差、钻井少等原因,研究区地质研究及油气发现主要集中在浅层,而对深层文昌组关注相对较少,缺少系统的源汇体系分析及有利砂体预测,制约了该区勘探进程.利用最新三维地震资料和钻井资料,在"源-汇"理论指导下对西江30洼陡坡带文昌组沉积体系进行了系统研究.结果表明:惠西低凸起中生界花岗岩为西江30洼提供物源,源区发育6个汇水单元,对应6个沟谷通道,并定量统计了汇水面积、集水高差、搬运距离、沟谷类型、宽深比等参数.基于地震沉积学及构造背景分析,认为西江30洼陡坡带垂向上发生了由扇三角洲向辫状河三角洲沉积体系的转换,文四段发育扇三角洲沉积,可识别出5个扇体,文三段发育辫状河三角洲沉积,可识别出3个朵叶体.惠州运动所引起的裂陷迁移和古地理格局的变化是西江30洼陡坡带发生扇-辫沉积体系转换的主要原因.通过源汇各要素相关性分析,明确汇水面积和搬运距离是控制西江30洼陡坡带砂体发育规模的主控因素,并指出F汇水单元输砂能力最强,其对应的文四段扇体4和文三段朵叶体3,展布规模最大,地震相特征最优,有利于优质储层发育,是下步勘探的有利区带.通过以上分析指明了西江30洼陡坡带文昌组勘探的有利方向,并且对陡坡型源汇体系研究提供了独特案例.

西湖凹陷平湖斜坡带北部孔雀亭含油构造油气资源丰富,但成藏过程复杂,其油气来源和充注过程尚不明确.通过油源对比及流体包裹体岩相学、均一温度、盐度、结合激光拉曼测试等多种方法,对孔雀亭构造油气来源、油气充注期次和成藏时间进行了分析.研究表明孔雀亭地区烃源岩主要分布在古近系始新统沉积的平湖组、宝石组地层,烃源岩类型包括煤、碳质泥岩和泥岩,有机质类型为Ⅱ1—Ⅱ2型;平湖组上、中、下段和宝石组烃源岩总有机碳含量(TOC)、生烃潜力(S1+S2)、氢指数(HI)等指标有所差异,其中平下段烃源岩有着较高的总有机碳含量;平湖组、花港组砂体多层系含油,油气地球化学性质均有差异,油源对比显示该区油气可划分为2类,Ⅰ类较低成熟度的油气来源于孔雀亭地区中低带平湖组下段烃源岩,Ⅱ类较高成熟度的油气可能来源于中低带宝石组烃源岩;平湖组储层发育2期流体包裹体,第1期气液两相包裹体发黄色、黄绿色、蓝绿色荧光,因经历再平衡作用,认为其捕获均一温度为130～140°C,成藏时期为5～2 Ma,以轻质油和凝析油充注为主;第Ⅱ期天然气包裹体呈灰色,无荧光显示,未经历再平衡作用,结合主峰均一温度140～150°C,认为成藏时期为2 Ma至今,以天然气充注为主,呈现晚期充注特征.激光拉曼检测到包裹体中含有沥青质,推测晚期可能伴有气洗作用.研究认为孔雀亭构造油气主要成藏时间为三潭组沉积至今,具备优良的储盖组合与构造演化的时空配置,具有"早油晚气,晚期成藏"的充注特点.

Reservoir fracability evaluation is one of the prerequisites to improve the effect of balanced fracturing of uncon-ventional oil and gas fields.At present,reservoir fracability evaluation mainly depends on logging data theory to explain rock mechanics parameters,and the application effect on fracturing is uneven.In this paper,the characteristics of rock mechanical parameters are directly reflected by the bit rock breaking data and the reservoir fracability is clustered by drilling and logging data.We established a reservoir fracability clustering model based on a self-organizing map(SOM)unsupervised clustering algorithm.The elbow method is used to determine the optimal clustering number,and the parameter optimization method of fracture placement is formed.The optimal design of three-cluster perforation placement is carried out for typical vertical wells in the Tarim Basin with large thickness reservoirs.The results show that the drilling time,dc-exponent,weight on bit,torque,true formation resistivity,acoustic and neutron data are significantly correlated with reservoir fracability and can be used as character-istic parameters.The established model can effectively distinguish the difference of reservoir fracability along the wellbore axis,and select the fractures in the fracturable well section of the same type of reservoir,which is expected to improve the effect of balanced fracturing.

研究了不同硅铝比NaY沸石先混合再进行铵离子交换和水热处理对USY沸石孔结构和酸性质的影响.对改性所得的USY沸石进行X射线衍射、低温氮气物理吸附脱附、固体铝核磁、氨气程序升温吸附脱附、扫描电镜、投射电镜等表征分析,结果表明,混合改性所得USY沸石的相对结晶度为70％,孔分布比较集中,介孔体积为0.200 cm3·g-1,最可几分布为10 nm,酸量较高.与高硅铝比NaY沸石单独改性所得USY沸石相比,能明显提高介孔体积和酸量.与低硅铝比NaY沸石单独改性所得USY沸石相比,能提高相对结晶度和酸量.与两种硅铝比NaY沸石分别改性后再进行机械混合所得的混合USY沸石相比,提高了酸量.混合改性USY沸石既含有丰富的介孔,又保留了较高的酸量.以重油为原料的催化裂化评价结果表明,混合改性所得USY沸石制备的催化剂与对比催化剂相比具有较好的重油转化能力,汽柴油总收率达到61.96wt％,焦炭收率为8.23wt％.

社会技术系统的日益复杂不仅滋生了更多潜在的安全问题,也促进了安全思维的不断改变.安全思维由基于事后响应的被动式管理向基于实时监控的主动式管理转变,事故模型也从简单线性思维发展到复杂系统思维.对事故模型功能和内涵的深刻理解有助于针对具体实际问题进行模型优选与开发.目前鲜有研究对安全思维及其与事故模型的关系进行深入探究,缺乏对各事故模型的特点、适用性和局限性的综合分析.本文在总结分析安全理念和思维发展历程的基础上,将事故模型划分为基于事件的因果链式模型、基于系统理论的事故模型和基于安全屏障的事故预测模型,从模型起源、功能和适用性等方面对3类模型中的代表性模型进行了综合分析,通过对比不同类别模型的优缺点和应用前景,展望了事故模型面临的挑战和未来的发展方向.

中东地区低渗孔隙型碳酸盐岩油藏开发潜力巨大,但其储层物性差,渗流能力低,压裂改造是解锁其商业潜能的关键手段,对达成中国石油"高速开采、快速回收"的开发目标具有重要意义.本文针对该类油藏压裂改造方式不明确,改造后单井产能差异较大等开发难题,开展了基于物模实验的合理储层改造方式论证和基于数模模拟的改造方式优化设计.通过真三轴物理模拟实验验证了低渗孔隙型碳酸盐岩储层压裂的可行性,明确了胍胶和滑溜水在压裂裂缝形态上的差异性.使用井下全直径岩心制作岩板,基于支撑剂导流能力实验确定了最佳支撑剂粒径和配比.基于中东某油田S油藏测井数据,建立了典型的地质力学模型和数值模拟模型,以净现值为目标,优化了低渗孔隙型碳酸盐岩压裂施工参数并形成配套施工工艺.研究结果表明:对于天然裂缝不发育或发育较少的低渗孔隙型碳酸盐岩储层,可使用水力加砂压裂进行储层改造,室内岩心压裂改造实验显示,利用滑溜水和胍胶的混合压裂液可形成相对复杂的裂缝形态.相同闭合压力下,支撑剂粒径越大,相应的导流能力越大.70～140目粒径支撑剂在30 MPa闭合压力下其导流能力不足3 D·cm.对于S油藏,当压裂段数为6段、射孔簇数为4簇、每段压裂液340 m3、每段支撑剂50 m3时,压裂效果最好.现场应用结果显示压裂效果良好.该研究成果对中东低渗孔隙型碳酸盐岩油藏经济高效开发具有一定的指导意义.

Unconventional oil and gas resources serve as vital replacement energy in China's hydrocarbon portfolio,and their efficient development is of great significance for safeguarding national energy security.The implementation of staged multi-clus-ter hydraulic fracturing in horizontal wells,along with the optimization of intra-stage cluster design parameters,is critical to maximizing the production potential of unconventional reservoirs.Clarifying fracture propagation mechanisms and quantifying the relationship between fracture geometry and well productivity is key to optimize intra-stage multi-cluster fracturing strategies.In this study,a phase-field method is employed to simulate the competitive propagation morphology of multiple fractures within a fracturing stage.A fracture morphology identification technique is integrated to construct a two-dimensional equivalent fracture model,which can characterize the stimulated flow pathways.Equivalent physical parameters after stimulation are extracted and transferred-together with geometric descriptors-as input for a discrete fracture flow model.This enables automatic coupling and data transfer between the geometric and flow models,thereby facilitating quantitative evaluation of production performance under different fracturing scenarios and ultimately achieving fully coupled fracture propagation-fluid flow simulation.The accuracy and feasibility of the dual-model coupling method are verified through comparison with laboratory-scale physical simulation experiments and field fracturing data.On this basis,the effects of intra-stage cluster number and cluster spacing on fracture morphology and production response are further investigated.The results show that,as the cluster spacing increases from 15 m to 25 m,the fracture deflection point shifts farther from the wellbore,and the tip deflection angle decreases from 30° to 24°.Meanwhile,the pressure gradient around the fracture tip is reduced,weakening the fluid driving force and significantly diminishing inter-fracture fluid interference.This change leads to a decline in peak daily oil production and stabilized production rate,with daily and cumulative oil output decreasing by 35.88%and 35.89%,respectively.In contrast,when the number of clusters per stage increases from 3 to 5,the deflection angle at the tip of the outer fractures increases from 30° to 34°,while the coverage of the induced stress field expands from 36.74%to 42.46%.This results in a higher pressure gradient surrounding the fractures,enhancing the fluid driving force and significantly improving oil mobilization.Consequently,peak daily and cumulative oil production increased by 40.49%and 45.467%,respectively.Therefore,optimizing the intra-stage cluster spacing and cluster number can effectively balance the degree of fracture interference and enhance single-well productivity,thereby improving the overall effectiveness of staged multi-cluster hydraulic fracturing in horizontal wells.

天然气水合物是一种清洁高效的潜在替代能源,提高开采效率对促进其产业化发展具有重要意义.本文借助开源程序HydrateResSim,针对具有强封闭性边界的第三类水合物藏薄层进行了直井和径向井降压开采天然气水合物产能模拟,对比了直井和径向井降压开采过程中温度场、压力场、水合物饱和度及产能变化规律,分析了径向井降压开采增产机理.模拟发现径向井降压开采能够显著降低近井区域的渗流阻力,增加储层中的有效泄流面积.通过促进压降向储层内部传播,径向井不仅扩大了水合物的分解范围,也减缓了开采过程中水合物的二次生成.由于水合物的分解是一个吸热过程,径向井开采水合物时所产生的低温区域不仅范围更大,且温度更低.相同压降条件下,径向井开采1000 d时累计产气量超过25万m3,是直井的3倍以上,累计产气产水比超过60,约为直井的2倍,表现出较好的增产潜力.研究表明径向井能显著提高水合物产能,有助于促进我国南海水合物早日实现商业化开发.

China is rich in shale oil resources.By the end of 2022,the predicted reserves of continental shale oil in China have reached 3 billion tonnes,but only recoverable shale oil has economic value under such reserves.The shale oil reservoirs of the Lucaogou For-mation in the Jimusar Sag can be divided into three types:interlayer type,lamina type and block type according to mineral composition and source-reservoir ratio.However,due to the large difference in pore structure characteristics and fluid occurrence state of the three types of reservoirs,the productivity difference is high using the same fracturing method.In order to clarify the pore structure character-istics of the Lucaogou interlayer and laminated reservoirs in the Jimusar sag and the difference of fluid mobility under their constraints,this paper studies the pore structure characteristics by means of XRD,casting thin sections,scanning electron microscopy and nitrogen adsorption.Nuclear magnetic resonance centrifugation technology was used to quantitatively evaluate the mobility of shale oil in laminated and laminated reservoir samples.The T1-T2 spectrum method was used to clarify the occurrence state of shale oil in different reservoir types.Finally,the main controlling factors of fluid mobility in shale oil reservoirs were analyzed by combining characteristic pore structure parameters.The results show that the carbonate content of laminated reservoirs is high,and the reservoir space is domi-nated by carbonate intergranular pores,clay mineral interlayer fractures and organic matter pores.The fluid component is dominated by kerogen,and the free oil component content is extremely low.The average value of movable fluid saturation is only 7.97%.The felsic content of the interlayer type is higher,the reservoir space is mainly composed of intercrystalline pores and dissolved pores in feldspar grains,the fluid composition is mainly movable oil,followed by bound oil and kerogen,and there is no movable water.The average saturation of movable fluid is 29.3%.The pore throat radius in the characteristic pore structure parameters is the main factor controlling the movable fluid saturation of shale oil reservoirs.The two are exponentially correlated,and the correlation coefficient can reach 0.95.Through the study,the main reservoir space types of the intergranular pores and intra-granular pores in the Lucaogou Formation and the laminar shale oil reservoirs in the Jimsal Depression are determined.The mobile fluid saturation decreases gradually from unimodal interlayer reservoirs to bimodal laminated reservoirs,but increases exponentially with the increase of the maximum pore throat radius.The results show that the maximum pore throat radius has a great influence on the mobile fluid saturation of shale oil reservoir.

连续管钻井完井技术是上世纪90年代初迅速发展起来的新技术,它具有作业效率高、成本低、安全可靠等优点.本文回顾世界连续管技术的发展概况,分析国内外连续管钻井和完井的技术现状;阐述连续管寿命及可靠性、变形伸长量、管内流体摩擦压降、钻井携岩和水平井冲砂洗井等连续管钻井完井相关基础理论研究进展;探讨连续管超临界CO2钻井、连续管非接触式破岩钻井、连续管无水压裂、连续管无限级压裂和连续管钻井与压裂改造一体化等前沿技术可行性与发展趋势;最后,展望连续管钻井和完井技术的发展前景.

Low-frequency distributed acoustic sensing in adjacent wells, a recently emerged fracturing monitoring technology, enables detailed diagnosis of hydraulic fractures. To promote industry understanding of recent advances in low-frequency distributed acoustic sensing technology for hydraulic fracture monitoring and facilitate its large-scale field application, this paper begins with the principles of distributed acoustic sensing. It briefly explains the sensing mechanism and well deployment methods, systematically summarizes research progress in numerical simulation, physical modeling, and field applications during hydraulic fracturing, and concludes by outlining future development directions for low-frequency distributed acoustic sensing technology. Research findings indicate that: ①Low-frequency fiber-optic acoustic sensing technology for hydraulic fracturing delivers high precision and real-time monitoring capabilities. This technology is increasingly being deployed for field fracture monitoring and has garnered significant attention from researchers worldwide. Disposable fiber optic systems offer distinct advantages including simplified deployment, low cost, compact footprint, and excellent value proposition. They represent a promising primary solution for future offset-well fracturing monitoring. Mitigating fiber slippage artifacts’ impact on strain response is therefore paramount for enhancing strain data fidelity in fiber optic sensing applications. ②Forward modeling primarily involves comparative analysis of simulated fiber optic strain fields with actual monitoring data to qualitatively characterize strain patterns. This establishes correlations between distinct fracture propagation types and their corresponding strain signatures, enabling interpretation of hydraulic fracture geometry and growth modes in offset wells. Current strain interpretation models predominantly consider two monitoring configurations: horizontal and vertical offset wells. However, these models fail to characterize fracture deflection induced by stress shadowing, resulting in discrepancies with field monitoring observations. Future work urgently requires developing sophisticated multi-fracture forward models that incorporate stress interference effects and fluid partitioning mechanisms to provide reliable guidance for field data interpretation. ③Inversion modeling primarily utilizes the Displacement Discontinuity Method(DDM) to construct fracture propagation models and solve for fracture dimensions. Current solution approaches include Least Squares, Picard iteration, Levenberg-Marquardt (L-M) method, and the Delayed Rejection Adaptive Metropolis (DRAM) algorithm. However, none can simultaneously invert fracture geometric parameters in all three spatial dimensions. Future inversion research must focus on optimizing solution algorithms, where effectively mitigating the impact of solution non-uniqueness will be the primary research focus for subsequent algorithmic enhancements. ④Physical simulation experiments primarily integrate distributed optical fiber interrogators based on Optical Frequency Domain Reflectometry (OFDR) technology with True Triaxial fracturing apparatuses to monitor fracture propagation. However, current experimental parameter configurations still fall short of fully replicating field conditions. Optimizing fiber deployment methodologies across diverse rock specimens and advancing the interpretation of laboratory-derived fiber optic data represent critical research priorities for future physical simulation studies. The study concludes that offset-well fiber optic monitoring demonstrates significant potential for interpreting hydraulic fracture dimensions. This technology holds considerable promise as a key enabling technology for addressing critical bottlenecks in unconventional resource development.

Karst-related carbonate fracture-cavity reservoirs play a vital role in global oil and gas field development.Especially under deep to ultra-deep conditions,their internal structures and filling-modification processes exhibit extreme complexity.Identifying the types and degree of fillings in paleokarst caves carries significant theoretical and practical value for evaluating effective reservoir space,optimizing development strategies,and tapping remaining oil potential.Based on an extensive review of the literature,this study proposes a systematic classification scheme for the filling phases and detrital filling phases of karst caves,highlighting key advancements in the geological understanding of internal cave filling structures.The article summarizes the current models of karst cave filling in the Tahe Area,focusing on technological progress in identifying and predicting filling materials and determining the degree of filling in paleokarst caves.Progress in identifying cave filling facies is primarily reflected in the genetic classification of modern surface cave detrital filling facies and the categorization of paleokarst cave fillings.Early methods for identifying and predicting cave filling materials and assessing filling degrees relied on qualitative and semi-quantitative approaches using logging and seismic data.With the advent of artificial intelligence(AI)technology,the application of machine learning's powerful generalization capabilities to identify and predict filling materials and degrees has emerged as a cutting-edge research direction in this field.The classification of filling modes in paleokarst caves suggests utilizing the coupling relationship between hydrogeology and cave development within the hierarchical structure framework of the paleokarst fracture-cave system.This approach,combined with the types of internal filling materials revealed by actual drilling data,facilitates the construction of filling models.However,current classifications of filling types in paleokarst caves primarily focus on differences in rock physical components,without adequately reflecting the dynamic mechanisms of filling formation.Additionally,the accuracy of identifying cave fillings remains insufficient,hindering the comprehensive determination of the sequence of fillings within caves.Currently,seismic inversion technology,commonly used for predicting cave fillings,can only estimate mud content and fails to accurately evaluate the degree of filling for all materials.Consequently,predicting the spatial distribution of filling degrees in paleokarst underground river networks requires further research and development.In light of these challenges,this article argues that leveraging AI technology to identify and predict the types and degrees of cave filling materials represents a promising trend.Future research should focus on improving the representativeness of sample sets,as well as the accuracy and generalization capabilities of prediction networks.

Currently,there is no comprehensive training dataset available for the modelling of fault-controlled karst caves using deep learning.In this study,we constructed prototype models for fault-controlled karst caves using outcrop data,seismic data,reliable geological models,and object-based methods.We combined,rotated,cropped,and selected prototype models from different sources to create a reliable and diverse training dataset for fault-controlled karst caves.Additionally,we constructed corresponding virtual well and probability map training datasets,all of which were used to train conditional generative adversarial networks(GANs).The trained generator convolutional neural network was applied to TH12330 well block,Tahe Oilfield.The generated multiple geological models for fault-controlled karst caves were consistent with geological patterns,conditioning well data,conditioning probability map data,and aligned with fracture structures,fractures,and cumulative production.This research explores the construction of a multi-source training dataset for fault-controlled karst caves and has achieved significant success in a real application example.Furthermore,it provides new insights into building reliable and diverse training dataset for deep learning modelling in other types of reservoirs.

本文详细阐述了全球尤其是北美页岩气开发现状,论述了Marcellus与Haynesville页岩气区的主要特征,认为持续技术创新、高效经营管理模式、多元产业扶持政策是美国页岩气飞速发展的主要驱动力,对我国页岩气的开发具有良好的借鉴作用.作者系统梳理了中国页岩气近 20 年的探索攻关与实践历程,认为历经评层选区、开发试验、示范区建设、海相页岩气规模开发4 个阶段,国内页岩气开发取得了重大成就,建成川南、涪陵等中深层页岩气大气田,实现了海相页岩气规模效益开发,2022 年产量达 238 亿方,成为我国天然气重要的供应来源,同时深层页岩气产能建设稳步推进,新区新层系勘探也取得重大突破.在深入分析我国页岩气地质与资源特征的基础上,文章论证了我国具备年产 500 亿～800 亿的开发潜力,但需要从完善页岩气立体开发配套技术、持续优化页岩气地球物理评价技术、加快钻井与压裂工程技术迭代升级、加大新层系新领域的勘探评价力度4个方面持续攻关.

In order to investigate the deformation characteristic and transport behavior of oil-water micro-interface and its evolution law under different wettability conditions in water flooding,a Hele-Shaw cylindrical model has been constructed based on the N-S equation.Phase field method has been employed to track the topological deformation characteristics of oil-water micro-interface in water flooding.The effect of wettability,oil-water viscosity ratio,and capillary number on the deformation characteristic and evolution process of oil-water micro-interfaces has been studied.The simulation results show that the dynamic evolution process of oil-water micro-interfaces observed from the model surface in water flooding can be divided into four stag-es,including breakthrough,fracture,three-phase contact line intersection,and micro-interface merging.The breakthrough and fracture phenomenon of oil-water micro-interfaces can be observed repeatedly in the displacement process,and is not affected by wettability and rock particle distribution.Three-phase contact line intersection and micro-interface merging phenomenon have the similar deformation characteristics and evolution law in the vertical profile of the model,which are mainly influenced by wet-tability and rock particle distribution.Three-phase contact line intersection phenomenon occurs more frequently under water-wet condition,while the micro-interface merging phenomenon occurs more frequently under oil-wet condition.The change amplitude of displacement front decreases and then increases in water flooding as wettability changes from strong water-wet to strong oil-wet,which exhibits the piston-like displacement under weak water-wet condition.The simulation results show that the highest oil displacement efficiency is observed under weak water-wet condition,while the lowest oil displacement efficiency(61.06%)is observed under strong oil-wet condition.Moreover,as the oil-water viscosity ratio increases from 20 to 100,the occurrence rate of three-phase contact line intersection phenomenon decreases,the micro oil displacement efficiency decreases by 8.56%,and the initial displacement pressure also increases under weak water-wet and the same injected pore volume multiple condition.As the capillary number increases from 0.66×10-3 to 2.0×10-3,the occurrence rate of three-phase contact line intersection phenomenon increases,the volumes of residual oil decreases,the micro oil displacement efficiency increases by 9.36%,and the displacement pressure also decreases under weak water-wet and the same injected pore volume multiple condition.This reveals that the micro oil displacement efficiency can be significantly improved by increasing the occurrence rate of three-phase contact line intersection phenomenon under water-wet condition.The research results can enrich the micro flow mechanism in water flooding,and provide a theoretical basis for further explore and utilize the residual oil.

Rock spontaneous imbibiton is the process of wetting phase fluid within the pore space spontaneously exhausting and driving the non-wetting phase,which is one of the important mechanisms for tight reservoirs to improve recovery.Due to the complexity of porous media characteristics and fracture morphology and other factors,the researches on imbibiton and mass transfer laws between fractures and pores have not yet been fully elucidated.In this paper,based on the phase field method and fluid motion equations,a pore-scale dynamic imbibiton and suction numerical model was established to analyze the mass transfer mechanism between fractures and pores within complex pore structures and the relationship with the recovery rate.The results show that:(1)the imbibiton process mainly covers three key stages inside the pore space:rapid penetration of the fracture,interaction between the fracture and the pore space,and gradual advancement in the pore space(i.e.,repulsion process).A faster injection rate will hinder the imbibiton process,and result in more residual oil retention.(2)There is a specific critical fracture width,and when the fracture width is about 40 times the average pore size,the recovery rate will fluctuate up and down in a certain range.As the critical fracture width decreases,the positive correlation between the fracture dimensionless number and the recovery rate is shown.(3)Fracture systems of different complexity have different effects on fluid transport.As the critical fracture width decreases,the impact of different fracture complexity on fluid mobilization is different.Specifically,with the increase of fracture complexity,the wave range of imbibiton effect become larger.The decrease of crack width will exacerbate the phenomenon of oil droplet aggregation,which will significantly slow down the recovery rate and cause clogging problems in the small pore area.(4)The number increase of the system open boundaries can effectively enhance the contact area of the wetting phase,which can maximize the dynamic utilization of the pore space,and form a synergistic seepage drive mechanism.The optimal imbibiton recovery was achieved under the four-sided open(AFO)condition,while the worst recovery was achieved under the one-sided open(OEO)condition.At the same dimensionless time,TEO and OEO show higher normalized recovery rates due to the strong non-homogeneous effect of the open number of end faces and spatial distribution model,while the recovery change curves of the remaining three boundary conditions show relatively concentrated trends.

煤层气藏数值模拟是煤层气水平井历史数据拟合以及生产预测的有效工具,但是计算耗时长,所需参数多.为了得到一个简单而精度足够的生产预测方法,由稳态解析的产能方程结合非稳态的边界条件可以得到煤层气井在线性流下的半解析模型.根据煤层气水平井的数值计算结果以及前人的研究成果,煤层在一维(线性或径向)非稳态渗流阶段流体饱和度和压力的关系随时间、空间变化不明显.本文通过煤层渗流控制方程推导了压力和饱和度的计算模型,并给出了由地层压力近似计算含水饱和度的方法,为气水两相渗流模型提供了计算基础.通过半解析模型与数值计算结果的对比,以及对沁水盆地两口水平井的历史数据拟合,验证了半解析模型的正确性和实用性.

在中国能源供需矛盾、结构性矛盾突出的情况下,如何提高炼油企业的能源效率成了亟待解决的问题;为了促进经济、能源与环境的可持续协调发展,提高能源利用效率有着极为重要的现实意义.为此,本文在分析影响炼油企业能源效率因素的基础上,构建了炼油企业能源效率评价指标体系,并运用组合赋权法确定各项指标的最终权重,进而建立了基于灰色关联TOPSIS的炼油企业能源效率评价方法.同时运用8家炼油企业的生产数据,对炼油企业的能源利用效率评价体系进行有效性检验.实证结果表明,该指标体系能够客观、有效地反映出炼油企业能源效率水平,可广泛用于评估炼油企业能源效率水平.

Total organic carbon(TOC)content is a crucial geochemical parameter for assessing reservoir quality and hydro-carbon generation potential of source rocks.The accurate prediction of TOC content is important for optimizing the exploration and development processes of shale oil and gas.With the rapid development of artificial intelligence technologies,individual machine learning algorithms have been increasingly applied to evaluate TOC content in shale.Despite the promising results of the individual machine learning algorithms,they are often subject to several challenges including overfitting,underfitting,and getting trapped in local optima of objective function.To address these limitations,the ensemble learning models are developed.Ensemble learning models leverage the strengths of multiple individual intelligent algorithms to enhance prediction accuracy and stability.Among them,combination strategy is one of the key factors in optimizing the ensemble learning models.Arithmetic average method as the simplest combination strategy fails to fully use prediction performance of the best individual intelligent model,and it can be severely affected by the individual intelligent model with a large prediction error,which can interfere with prediction outcome of overall model.In comparison,weighted summation method as a common combination strategy assigns the weights to different individual intelligent models according to their performance on training data.This method will perform excellently on training set,but it tends to have a poor performance when applied to test set.This paper develops an ensemble model based on an intelligent matching technology(IMTEM).The proposed method utilizes a set of robust intelligent algorithms including extreme gradient boosting,random forest,support vector machine,and extreme learning machine as algorithm modules to initially process input data.Then,the processed feature information combined with original log responses is fed to feedforward neural network layer for nonlinear transformation and feature learning,thereby enabling accurate and continuous estimation of TOC content in shale.To validate effectiveness of the IMTEM,the proposed method is applied to the prediction of TOC content in the Longmaxi Formation shale in the Sichuan Basin.Test results indicate that,compared to two ensemble models,five baseline models,and the ΔlogR method,predictions of the IMTEM exhibit higher consistency with measured TOC content.This demonstrates that the IMTEM is more suitable for predicting TOC content in shale.

The Tarim Basin, functioning as China's strategic hydrocarbon resource succession zone, encounters globally recognized technical bottlenecks in the exploitation of deep/ultra-deep reservoirs. A comprehensive chronological analysis is conducted on the development trajectory of stimulation technologies for ultra-deep hydrocarbon reservoirs in the Tarim Oilfield, particularly highlighting stimulation technology breakthroughs implemented in the field’s dual primary production zones: For complex carbonate reservoirs in ultra-deep intracratonic basins, an innovative integrated design approach for fracture-cavity-system identification and stimulation was proposed; for ultra-deep fractured classic reservoirs in the Kuqa piedmont zone, a series of high-efficiency stimulation technologies were developed. The research has achieved three major technological breakthroughs: First, the successful development of high-temperature resistant acid systems has significantly enhanced stimulation effectiveness in ultra-deep reservoirs; second, the breakthrough in high-density weighted-fracturing fluid technology provides critical support for ultra-deep well stimulation; third, continuous innovations in supporting process technologies have established a solid foundation for efficient development of ultra-deep oil and gas reservoirs. Integrating exploration trends with development challenges of ultra-deep oil and gas reservoir in the Tarim Basin, the paper addresses the production demands and existing technical deficiencies in reservoir stimulation, including: the fundamental laboratory research on deep/ultra-deep reservoir stimulation, artificial fracture propagation mechanisms, development gaps in novel stimulation fluids, zonal isolation tools, temporary plugging materials and supporting application techniques, limitations in real-time monitoring and interpretation technologies for stimulation operations. Six key technical recommendations are proposed: (1) Establishment of an ultra-high temperature/pressure experimental platform to conduct fundamental research on rock mechanics, fluid flow, and conductivity testing; (2) Investigation fracture propagation mechanisms in high-stress complex reservoirs and develop a multi-physics coupled fracture growth model; (3) Development of high-performance acid systems resistant to 200 °C, with breakthroughs in weighted, low-friction, thermal-stable, and controlled-acid-generation technologies; (4) Development of engineer stratified stimulation tools (including diverting agents and supporting techniques) to optimize treatment in interbedded formations; (5) Enhancement of “multi-cluster limited-entry” fracturing for ultra-deep horizontal wells to improve fracture-controlled reserves; (6) Implemention of real-time fracture diagnostics using fiber-optic monitoring and develop high-temperature downhole monitoring tools. This study not only systematically synthesizes the stimulation technology framework for “triple-ultra” (ultra-deep, ultra-high temperature, ultra-high pressure) reservoirs in the Tarim Oilfield, but also establishes critical technological foundations for China’s 10 000-meter-depth reservoir stimulation endeavors. The research outcomes provide significant theoretical value and engineering guidance for promoting efficient development of deep hydrocarbon resources in China, while the innovative technological approaches may also serve as valuable references for global oilfield development under analogous geological conditions.

As a critical technical approach for shale reservoir development,dynamic imbibition displacement during the fractur-ing stage has emerged as a focal point in reservoir engineering research over recent years.In light of global energy demands and ongoing exploration of unconventional oil and gas resources,the significance of this technology in enhancing the exploitation of shale oil reservoirs cannot be overstated.However,the specific mechanisms of dynamic imbibition process in shale oil reservoirs influenced by various factors still aren't unclear,and it's difficult to accurately quantify their impact on imbibition oil production efficiency.These uncertainties significantly hinder further improvement in the development efficiency of shale oil reservoirs,lead to higher development costs and bring huge challenges to sustainable resource development. Aiming at the unclear dynamic imbibition mechanisms and action laws of shale oil reservoir,a core-scale numerical simulation model was established,and the control variable method was adopted to set up 15 simulation schemes.By these methods,the mechanisms of displacement pressure difference,capillary radius,wetting angle and oil-water viscosity of dynamic imbibition displacement effect,and the change laws of fluid seepage were revealed.The effects of displacement pressure difference,capillary radius,wetting angle,and oil-water viscosity on the effectiveness of dynamic imbibition oil recovery,and the laws of fluid seepage changes were clarified in this study.The results show that:During dynamic imbibition,as the capillary radius increase from 0.1 μm to 10 μm,capillary force decrease and fluid seepage rate accelerates,leading to 8.0%increase in imbibition recovery.Along with the displacing pressure difference increases from 0 MPa to 3 MPa,the imbibition upgrades from static to dynamic,and the imbibition recovery degree increases by 7.9%.It is considered that the displacing pressure difference and the recovery degree are in accordance with the power function relationship,and there is an optimal displacing pressure difference.With changes in rock wettability from hydrophilic to neutral or oleophilic,extraction degree decreases from 48.9%for water-wet conditions to 33.9%for oil-wet conditions.As crude oil viscosity decreases from 53.3 mPa·s to 13.99 mPa·s,imbibition recovery rate increases by 9.1%;the higher the viscosity of water phase,the smaller the initial imbibition velocity,but the better the imbibition displacement effect.In oil field operation,by optimizing injection pressure,selecting suitable fracturing fluid and surfactant,the hydrophilic degree and displacement phase viscosity can be improved,and the dynamic imbibition process can be improved to increase the oil displacement efficiency.In the future,the complexity of multiphase flows and the heterogeneity of reservoirs should be further considered to study the influence of various factors on the dynamic imbibition process of shale from different scales.

地下储气库作为大型天然气管网系统的重要组成部分,确保其安全可靠运行对保障管网系统的供气能力尤为重要.本文针对枯竭油气藏型地下储气库的工艺特点和功能分区,将储气库系统工艺流程分为采气工艺和注气工艺;功能区块分为地下储层、注采井系统和地面系统.通过注采井系统将地下储层和地面系统联系起来,并采用基于一体化的可靠性分析方法,计算给定注采任务下,储气库系统的运行可靠性.最后,以某储气库为例,对其运行可靠性进行评价.

The submarine fan is an important reservoir for oil and gas in deep water areas. The differences in reservoir quality have a significant impact on the differential accumulation and exploitation of oil and gas. Previous studies have conducted extensive research on the differences in reservoir quality of submarine fans. However, the characteristics and distribution patterns of reservoir quality differences within submarine fans under a steep continental slope background are still unclear. This paper takes the Oligocene submarine fan reservoir in the X gas field of the Rovuma Basin in East Africa as the research object. By integrating core, well logging and seismic data, an in-depth study has been carried out on the control of reservoir quality differences and distribution patterns of submarine fan sedimentary microfacies and lithofacies under the steep continental slope background. The results show that the changes in reservoir quality within the submarine fan are mainly controlled by rock texture, lithofacies (association) and sedimentary microfacies under the circumstance of weak diagenesis. Grain sorting and clay content mainly control the porosity and permeability of the reservoir, respectively, but the relationship between grain size and reservoir properties is very complex. In sand-rich lithofacies, fine sandstones have the highest porosity due to their good sorting, and massive gravel-bearing coarse sandstones have the highest permeability due to their low clay content. Under the steep continental slope background, the submarine fan sedimentary microfacies are arranged in the order of muddy channel-sandy channel-lobe main body-lobe edge along the source direction, resulting in the source-directional differences in reservoir quality in the order of “poor, good, and poor”. The proximal muddy channel consists of fine-grained and clay-rich lithofacies, with overall poor physical properties. In the middle position, the sandy channel and lobe main body change to massive gravel-bearing coarse sandstone lithofacies and medium-coarse sandstone lithofacies, with low clay content and improved to good physical properties. Among them, the reservoir quality of the sandy channel is better than that of the lobe main body. The internal high porosity and high permeability zones of the sandy channel are in the form of elongated lenses, while the relatively high porosity and high permeability areas of the lobe main body are in the shape of lobes. The distal lobe edge changes to fine-grained lithofacies (fine-medium sandstone, fine sandstone) with increased clay content and gradually deteriorated physical properties.

Distributed fiber optic monitoring in adjacent wells has increasingly become an essential technique for fracture surveillance during hydraulic fracturing of unconventional oil and gas reservoirs. Developing forward models for distributed fiber optic strain response in adjacent wells is of significant importance for understanding the mechanism of fiber response and for the inversion of fracture geometries. However, existing forward interpretation models face limitations from insufficient flexibility in the selection of fracture propagation models, and by computational inefficiency caused by grid-based discretization, especially when high precision is required. To address these limitations, this study presents a semi-analytical stress-displacement field model for simulating fracture propagation with arbitrary aperture and geometric shape. Based on this, a forward modeling framework for adjacent well distributed fiber optic strain response is established. Using a penny-shaped fracture as a representative example, the stress field around the fracture is calculated and benchmarked against the classical Sneddon analytical solution. A forward simulation of fiber optic strain response for a scenario where a horizontal adjacent well monitors a vertically oriented elliptical fracture is conducted. The results are compared with the forward-modeled strain response from the Displacement Discontinuity Method(DDM). The results reveal strong consistency between the semi-analytical model and both the analytical and DDM solutions in classical benchmark cases, confirming the model’s validity and applicability. The model is further coupled with various fracture propagation models and applied to the interpretation of real field data. In particular, distributed fiber optic monitoring results from Stage 19 of Well B1H and Stage 20 of Well B2H in the Hydraulic Fracturing Test Site 2 (HFTS-2) project in the United States are analyzed. The modeling results show that the proposed approach accurately reproduces the characteristic patterns observed in field fiber data. For Stage 20 of Well B2H, which exhibits higher-complexity response characteristics, the model provides a closer match to observed details and temporal evolution compared with the DDM-based approach. In conclusion, this study establishes a semi-analytical forward modeling approach for fiber optic strain in adjacent wells under arbitrary fracture aperture and geometry, significantly reducing computational cost and improving efficiency. The model’s flexibility enables seamless integration with a variety of fracture propagation models, enhancing its capacity to accurately capture complex fracture behaviors observed in field monitoring. This provides a powerful tool for detailed interpretation and analysis of distributed fiber optic data in adjacent well applications.

With the increasing difficulty of oil and gas resources extraction,rotary guided drilling has become an important technology for controlling the trajectory of the borehole and connecting the reservoir.In the process of rotary guided drilling,it is often necessary to add plugging agent with drilling when encountering formation leakage,but the small-sized plugging materials mainly used nowadays may reduce the plugging effect,especially fiber-based materials,which,due to their large length-to-di-ameter ratios and easy to be intertwined,will lead to an increase in the viscosity of the drilling fluid,and in serious cases,trigger stuck drilling.In this paper,a kind of plugging fiber with drilling was developed and compared with the fiber material for plugging rotary guide screen in the field.The results show that the developed fiber complies with the industry standard and has good performance of over-spinning conductivity and pressure-bearing plugging performance.After adding 3%modified fiber to the drilling fluid system,it can effectively block 20～40 mesh quartz sand at 150℃and 6 MPa,and the cumulative leakage is only 4 mL in 30 min.This study is of great significance for the selection of plugging materials for rotary guided drilling tools.

Multiphase flow in porous media is an important research topic in the field of oil and gas reservoir development.Due to the complex geological conditions in China,properties of rocks,such as permeability and porosity,are complex and hetero-geneous.The numerical solution for the complex multiphase flow problems needs to overcome challenges such as the system's multiple variables,strong nonlinearity,large computational cost,and the preservation of physical properties.For the traditional incompressible and immiscible two-phase flow model,the IMplicit Pressure Explicit Saturation(IMPES)semi-implicit scheme is a widely-used important algorithm for solving such problems,where the pressure equation is solved implicitly,and the saturation is updated explicitly.However,the traditional IMPES scheme requires the calculation of saturation gradients when updating the saturation.Therefore,it is not suitable for solving the two-phase flow problems in complex heterogeneous media.Hoteit and Firoozabadi proposed an improved IMPES method,allowing the method to reproduce discontinuous saturation in heterogeneous media.However,these two IMPES methods only update the saturation through the mass conservation equation of one phase of fluid,they cannot guarantee that the other phase of fluid also satisfies the local mass conservation property.The derivations of the pressure equations for these two IMPES methods are obtained by adding the volume conservation equations of each phase at the continuous level of partial differential equations,and then using incompletely matched spatial discretization methods for the pressure equation and the saturation equation.Therefore,it is impossible to simultaneously ensure the local mass conservation of each phase for the two-phase fluid.In this paper,based on several types of novel IMPES semi-implicit schemes for solving two-phase flow in porous media that we have published in recent years,we propose a new framework for deriving the pressure equation in IMPES.That is,we first discretize the volume conservation equation of each phase using a spatial discretization method with local conservation,and then add up the discretized volume conservation equations of each phase.In this way,a complete match in spatial discretization between the pressure equation and the saturation equation is achieved.Essentially,it overcomes the difficulty in previous literatures that the IMPES semi-implicit method cannot simultaneously ensure that both phases of the fluid satisfy local mass conservation.The novel IMPES method ensures that each phase of the fluid satisfies local mass conservation,the saturation is bounded,the computational scheme is an unbiased solution,and it is suitable for solving two-phase flow problem with different capillary pressure distributions in heterogeneous porous media.The novel phase-wise conservation IMPES framework proposed in this paper also has an advantage that the traditional IMPES does not have.That is,in the novel phase-by-phase conservation IMPES framework,it is only necessary to define the spatial discretization method of the volume conservation or mass conservation equation,and there is no need to separately define the spatial discretization method of the pressure equation.The solutions of several types of novel IMPES semi-implicit schemes that we have published in recent years can be regarded as special cases of the novel phase-by-phase conservation IMPES framework proposed in this paper.The IMPES framework in this paper can also be applied for more complex multi-component and multi-phase flow in porous media to construct more novel schemes.At the same time,through numerical examples of heterogeneous porous media,this paper verifies the effectiveness and superiority of the novel IMPES method in dealing with two-phase flow problems under complex geological conditions.Compared with the traditional method,it is more adaptable,more stable,and more efficient.