条带曲率裂缝发育区页岩气井裂缝扩展规律——以涪陵页岩气田焦石坝西南区块为例

Fracture propagation law for shale gas well in strip-curvature-crack development area:a case study of Southwest Jiaoshiba Block in Fuling shale gas field

陈新安 2

中国石化重庆涪陵页岩气勘探开发有限公司，重庆 408014 中国石化江汉油田分公司石油工程技术研究院，湖北 潜江 433111

Fuling Shale Gas Exploration and Development Ltd., SINOPEC, Chongqing 408014, China Research Institute of Petroleum Engineering, Jianghan Oilfield Company, SINOPEC, Qianjiang 433111, China

为降低条带曲率裂缝发育区页岩气水平井压裂施工难度，提升压裂改造效果，研究条带曲率裂缝对压裂裂缝扩展的影响规律很有必要。为此，选取条带曲率裂缝发育区的焦页A井和条带曲率裂缝发育程度低区的焦页B井，运用井中微地震监测手段对2口井的裂缝扩展情况进行实时监测，同时结合压裂施工特征，对比研究条带曲率裂缝对页岩气压裂裂缝扩展的影响规律，并提出针对性的施工对策。结果表明：压裂裂缝缝网轮廓形成的速度因条带曲率裂缝发育情况的不同会有差异，条带曲率裂缝发育区轮廓形成较快；条带曲率裂缝发育区页岩气井压裂初期破裂压力梯度低，压裂裂缝延伸呈多缝发散特征，且发散程度高，波及范围较大，中后期延伸压力梯度小，液体滤失严重，近井易沉砂，施工难度高，砂堵概率大，影响试气效果；针对性提出的施工对策可有效降低施工风险，提高改造效果。该研究为条带曲率裂缝发育区页岩气井压裂方案优化提供了依据和参考。

In order to reduce the difficulty of fracturing construction of shale gas horizontal well in strip-curvature-crack development area and improve the effect of fracturing, it is necessary to study the law of fracture propagation. For this, the micro-seismic monitoring method was used to monitor the A Well in strip-curvature-crack development area and the B Well in curvature-crack undeveloped area. Combined with the construction characteristics, the law of impact of the strip-curvature-crack on the fracturing crack propagation was studied, and targeted construction countermeasures were put forward. The results show that the speed of the formation of fracture network varies with the development of the cracks, and it forms faster in strip-curvature-crack development area; the fracturing pressure gradient is low and the fracturing propagation of fractures is characterized by multiple fractures with the higher degree of divergence and larger range in the early stage of fracture; in the medium-late extension stage, the characteristics of small extension pressure gradient, serious loss of liquid, being easy to sink near the well, high difficulty construction and sand blocking probability affect the test production of gas; construction countermeasures are proposed to reduce the construction risk effectively and improve the effect of fracturing. These results can provide a basis for the optimization of shale gas fracturing scheme in strip-curvature-crack development area.

10.6056/dkyqt201806011