水力喷射径向钻井转向器的通过摩阻影响因素分析

水力喷射径向钻井技术是一种低成本、增油效果明显的增产措施,在陆地油田广泛应用,但由于海上油田的作业成本较高,其要求钻进更长的水平段长度以提升增油效果,而减小转向器段摩阻是增大径向水平段长度的重要手段。采用自主研发的过转向器测试系统进行实验,研究了转向器结构参数对过转向器摩阻的影响规律,并通过灰色关联分析法分析了各结构参数的影响程度。研究结果表明,随着转向器内转角、外转角和转弯半径的增大,转向器的通过摩阻都有所减小;各参数影响敏感性从大到小依次为转向器内转角、转向器转弯半径、转向器外转角,进行转向器设计时,优先考虑降低内转角以降低过转向器摩阻,从而增加水平段极限钻进长度。研究成果可对今后转向器结构参数的设计以及该技术早日在渤海油田应用提供参考。

Analysis of influencing factors on the passing friction of the converter during hydraulic-jet radial drilling

Hydraulic-jet radial drilling technique is one stimulation measure with the characteristics of low cost and remarkable stimulation effect and it is widely applied in onshore oilfields. As for offshore oilfields, however, the operation cost is higher and longer horizontal sections are needed to improve stimulation effects. Reducing the frictional resistance in the interval of converter is one important method to increase the radial horizontal section length. the independently developed through-converter testing system was adopted to experimentally study the influential laws of converter’s structural parameters on through-converter frictional resistance. Then the influential degree of each structural parameter was analyzed by means of gray association analysis method. It is indicated that through-converter frictional resistance decreases as the internal corner, external corner and turning radius of the converter increase. The influential sensitivity of each parameter is ranked from the top the bottom as internal corner, turning radius and external corner of converter. Therefore, to design a converter, the priority shall be given to the reduction of internal rotation angle to reduce the through-converter frictional resistance, so as to increase the ultimate drilling length of horizontal section. The research results provide the reference for the future design of converter’s structural parameters and the application of this hydraulic-jet radial drilling technique in the Bohai Oilfield as soon as possible.