低渗透储层水淹油井堵水压裂技术研究与试验

摘要

为了提高水淹油井的单井产量,根据油井不同见水类型,研究形成了不同水淹类型油井堵水压裂技术.针对孔隙性见水油井,研究形成了选择性堵水压裂技术,选择性堵水剂的堵水率是其堵油率的3.3倍,具有较高的选择性封堵能力.针对裂缝性见水油井,研究形成了封堵老缝定向射孔压新缝技术:其裂缝固化剂固化后体积变化小于5％,突破压力高达9.8 MPa;定向射孔根据老井剩余油分布情况,选择射孔方位,以控制压裂裂缝延伸方向.现场2口井试验表明,堵水压裂后平均日增油分别为0.81和0.76t,具有较好的增产效果,为长庆低渗透储层水淹油井提高单井产量提供了有效的技术手段.%In order to restore or improve the production of single water flooded well, different plugging & fracturing technologies were developed for such wells depending on types of water breakthrough. For pore-breakthrough well, the selective plugging & fracturing technology was defined; the selective water plugging agent was highly capable of selective plugging, with rate 3. 3 times that of the oil plugging rate. For fracture-breakthrough well,the technology of plugging old fractures and directional perforating to create new fractures was proposed;the fracture volume changed by less than 5% after solidifying of the agent, with breakthrough pressure up to 9. 8 MPa; according to the residual oil distribution of old well, the azimuth of directional perforation was selected to control the extension direction of fractures. By field test in 2 wells,it was found that the average daily oil increment is 0. 81 t and 0. 76 t respectively after water plugging and fracturing,indicating better stimulation effects. Therefore, these technologies provide effective solutions to improve the production of single water-flooded well in low-permeability reservoir of Changqing Oilfield.