大庆外围砂煤互层压裂工艺技术研究

大庆外围探区油气资源丰富,包括致密油以及致密砂岩气、煤层气等非常规油气资源。煤层具有杨氏模量低、泊松比高、节理发育等特点,对于砂煤互层类低渗透砂岩储层,水力压裂时裂缝容易穿入煤层或沿砂煤界面延伸,造成高停泵、裂缝扭曲、裂缝形态复杂等现象。同时由于煤层动态滤失大,易造成局部过液不过砂,加大施工难度,导致目前施工成功率低。综合分析国内外致密砂岩气及煤层气技术发展现状,开展了砂煤互层压裂工艺技术研究,通过岩石力学测试及应力精确解释,结合现场试验,形成压裂优化设计及现场施工工况诊断、分析控制方法,现场试验效果良好,为非常规储层压裂深入开展研究奠定了基础。

Study on Hydraulic Fracturing Technology For Sand Coal Interbedding Layers of Daqing Peripheral Oilfield

The exploration zone of Daqing peripheral oilfields have abundant oil and gas resources which are unconventional oil and gas resources including tight oil ,tight sandstone gas and coalbed methane. The coal bed has the factures that Young's modulus is low, Poisson's ratio is high and joints are development. For low permeability sandstone reservoir of sand coal interbeding layer, the fractures wear into coal bed or extend along the sand easily during hydraulic fracturing. This can lead to the phenomenon such as high pump off, fracture contortion, fracture morphology complex. Liquid is allowed to pass through, the sand is not allowed to pass in part of the coal bed because of high dynamic filtration. This will lead to the construction difficulty and low success ratio. Base on the current development situation of the tight sandstone gas and coalbed methane technology at home and broad, the research of hydraulic fracturing technology of sand coal interbedding layers was carried out. Combined with the field experiment, the method of fracturing optimization design, field construction condition diagnosis and analytical control was formed. The method worked well in the site experiment and laid the foundation of conducting further research of unconventional reservoir fracturing.