摘要： 旋转磨料射流喷射钻进径向水平井是经济高效开发碳酸盐岩油藏的潜在有效手段.基于旋转磨料射流破碎灰岩室内实验,证实了其碳酸盐岩储层喷射钻进可行性、揭示了关键参数对破岩效果的影响规律、优选了最优作业参数组合,并探析了岩石破碎机理.研究表明:旋转磨料射流冲击灰岩形成一个规则光滑、底部存在凸起的圆形孔眼,孔眼剖面为"W"型,孔眼直径大于入井管串的最大外径,且凸起可被后续射流剥蚀而不影响管线连续送进,证实了其碳酸盐岩储层喷射钻进可行性;成孔直径随喷射压力、喷射距离、喷射时间的增加而增加,随磨料质量浓度的增加先增加后减小;成孔深度和体积随喷射压力、喷射时间的增加而增加,随喷射距离的增加而减小,随磨料质量浓度的增加先增加后减小;本文实验条件下的最优作业参数组合为射流压力 30 MPa、喷射距离 0、磨料质量浓度 9.0%～10.0%、喷射时间 60 s;在旋转磨料射流破碎碳酸盐岩过程中,其不单以磨料颗粒大角度冲击下产生的拉伸作用破岩,同时还伴以磨料颗粒小角度冲击下产生的剪切作用破岩,由于岩石抗拉、抗剪强度远低于其抗压强度,从而使得旋转磨料射流具有较高的破岩能力和破岩效率.研究结果可望为旋转磨料射流喷射钻进径向水平井开发碳酸盐岩油藏提供理论依据和实验基础.

关键词: 旋转射流, 磨料射流, 岩石破碎, 径向水平井, 碳酸盐岩油藏

Abstract: Radial swirling impeller abrasive water jet drilling technology is a potential cost-effective way to develop carbonate reservoirs.Swirling impeller abrasive water jet carbonate rock breaking experiments are utilized to study the feasibility of drilling radial branches in carbonate reservoirs.Besides,the influence low of process parameters and optimal process parameter combination on the swirling impeller abrasive water jet carbonate rock breaking performances are studied and illustrated.Finally,the carbonate rock breaking mechanisms of swirling impeller abrasive water jet are discussed and revealed.The results of this study showed that the swirling impeller abrasive water jet could create a regular smooth circular hole with a conical bulge at the hole bottom.The cross-section of the swirling impeller abrasive water jet drilled hole presented a"W"-shape.The jet drilled hole diameter was greater than the maximum outside diameter of the jetting pipe string and the conical bulge at the hole bottom could be eroded by the subsequent jet,which proofed that it was feasible for the swirling impeller abrasive water jet to drill radial branches in carbonate reservoirs.The jet drilled hole diameter increased with the increase in the jetting pressure,the standoff distance and the exposure time.And,it increased firstly and then decreased with the increase in the abrasive mass concentration.The jet drilled hole depth and hole volume increased with the increase in the jetting pressure and the exposure time,and with a decrease in the standoffdistance.And,they increased firstly and then decreased with the increase in the abrasive mass concentration.The optimal process parameter combination under our experimental conditions was the jetting pressure,standoff distance,abrasive mass concentration and exposure time were the 30 MPa,0,9.0%～10%and 60 s respectively.In the process of swirling impeller abrasive water jet carbonate rock breaking,the swirling impeller abrasive water jet not only through the tension force that was created by the high angle abrasive particle impact,but also through the shear force that was created by the low angle abrasive particle impact to break the carbonate rock.Since the tensile strength and shear strength of carbonate rock material was far small than the compressive strength,the swirling impeller abrasive water jet possessed a high rock breaking ability and efficiency on carbonate rock.The research results were expected to provide a theoretical basis and experimental foundation for utilizing the swirling impeller abrasive water jet to drilling radial branches in carbonate reservoirs.

Key words: swirling jet, abrasive jet, rock breaking, radial jet drilling, carbonate reservoir

中图分类号: 

• TE242 TD353