压裂水平井裂缝参数优化研究

裂缝是影响压裂水平井产能的主要因素,为了成功的压裂水平井,在压前的施工设计中要充分考虑裂缝参数的优化.利用电模拟实验研究了裂缝参数与压裂水平井产能的关系,所考虑的裂缝参数包括水平井筒与裂缝夹角、裂缝长度、水平井筒长度、裂缝数目、裂缝位置及裂缝间距等.研究表明产能随水平井筒与裂缝夹角的增大而增大,超过45°后产能增加的趋势变缓;产能随裂缝长度的增加而增加,但在具体的油藏地质条件下存在最优的裂缝长度和水平井筒长度的匹配;实验中压裂水平井的最优裂缝数为3~5条,其中外裂缝对产能的贡献最大;产能随裂缝间距的增大相应增加.裂缝参数的优化研究可为压裂水平井的施工设计提供理论性指导.

Optimization of the fracture parameters of fractured horizontal wells

The fractures are the most important factor of affecting the productivity of a fractured horizontal well. In fracturing design, it is necessary to well optimize fracture parameters for successfully fracturing horizontal well. The relationship between the productivity of a fractured horizontal well and its fracture parameters, including the angle between fracture and horizontal wellbore, fracture length, horizontal wellbore length, fracture number, fracture location and spacing between fractures, is studied by electric analogy experiments. It is shown that, the productivity increases with the increase of the angle, which slows down when the angle exceeds 45°; the productivity increases with the increase of the fracture length, but there is an optimum matching of the fracture length with the wellbore length under specific reservoir conditions; the optimum fracture number in the experiment is 3～5, and the outer fractures have the greatest contribution to the productivity; the productivity increases with the increase of the fracture spacing. Thus, the optimization of fracturing parameters can provide the guidance for the design and construction of a horizontal well fracturing.