延川南煤层气田V形水平井组压裂技术

延川南煤层气田存在单井产气量低、生产成本高和投资回收期长的问题,为此,进行了煤层气V形水平井组压裂技术研究。在统计该气田已压裂井裂缝方位的基础上,预测待压裂井的裂缝方位,依据煤层厚度及2口水平井水平段的埋深与夹角设计裂缝位置及裂缝长度,并优选分段压裂工艺、压裂液、支撑剂及压裂参数,形成了延川南煤层气V形水平井组压裂技术。该压裂技术在延川南煤层气田3组V形水平井组进行了应用,累计压裂29段,平均每段用液量881 m3、加砂量49.4 m3,压裂成功率90%,平均产气量是定向井的6.18倍,投入产出比低于定向井。现场应用表明,煤层气V形水平井组压裂技术可以提高单井产气量,降低生产成本,缩短投资回收期。 

Fracturing Technology for a V-Shaped Horizontal Well Cluster in the Yanchuannan CBM Field

The Yanchuannan CBM Field is characterized by low single-well gas production, high production cost, and long payback period to recover the initial investment. In order to solve these problems, the V-shaped horizontal well cluster fracturing technology was studied for CBM development. Based on the statistics of fracture azimuths in the wells fractured in this CBM Field, it was possible to predict the fracture azimuths of wells to be fractured. Considering the coalbed thickness and the burial depth as well as inclined angle of horizontal section in two horizontal wells, the fracture positions and lengths were designed. After optimizing staged fracturing, fracturing fluids, proppant and fracturing parameters, the fracturing technology for V-shaped horizontal well cluster in the Yanchuannan CBM Field was established. This technology was applied in three V-shaped horizontal well clusters in the South Yanchuan CBM Field, cumulative fracturing were 29 stages, average fluid volume in each stage was 881 m3,the proppant volume added was 49.4 m3. As a result, the fracturing success ratio reached 90%, the average gas production of horizontal well was 6.18 times of that of directional well, and the input-output ratio was higher than that of the directional well. Field applications demonstrated that the fracturing technology for a V-shaped horizontal well cluster can enhance single-well CBM production, reduce the production cost, and shorten the payback period of investment.