胜利油田致密油储层体积压裂技术及应用

Application of volume fracturing technology in tight oil reservoirs of Shengli oilfield

胜利油田致密油储量丰富,储层埋藏深、物性差、岩性复杂,常规压裂后产量低、递减快,开发效益差。通过技术攻关和配套完善,形成了适合于致密油储层的组合缝网压裂等压裂新工艺,在提高改造体积的同时,大幅度提高裂缝导流能力,提高压后效果,并针对纵向多层系油藏特点,形成了水平井多级分段压裂和直斜井多级分段压裂两类改造模式;研发了可以在线连续混配施工的速溶型低浓度瓜尔胶压裂液体系,以及可与地表水、热污水混配、可回收再利用的乳液缔合型压裂液体系,有效解决了大规模连续施工压裂液的配置、水源等问题;同时完善了井工厂实施模式和裂缝监测技术。应用该技术成功开发了Y227、Y22、Y104等致密油区块,大幅度提高了单井产能、延长了有效期,提高了区块开发效益,带动了一批难动用储量投入有效开发,大幅提高了胜利油田致密油藏经济有效动用程度。

The Shengli oilfield is rich in tight oil reserves,but the reservoirs characterized by deep burial,poor physical properties and complex lithology,leading to unsatisfactory development performance like low yield and fast production decline after conventional fracturing stimulation.Through researches and optimizations,new fracturing techniques,such as commingled fracture network stimulation,were developed for tight oil reservoirs.While increasing the stimulated reservoir volume(SRV),these techniques can greatly improve fracture conductivity and post-fracturing performance.For the reservoirs with multiple layers vertically,two types of treatments were established,i.e.multi-stage fracturing of horizontal wells and multi-stage fracturing of vertical/deviated wells.A fast-dissolving low-concentration guar fracturing system that can be continuously mixed on line and a recyclable emulsion-associating fracturing fluid system that can be mixed with surface water and hot sewage were developed,which can effectively ensure the fracturing fluid preparation and water source for large-scale continuous fracturing operations.Moreover,the well-plant operation mode and fracture monitoring technique were upgraded.The proposed technology has been successfully applied in tight oil blocks such as Y227,Y22 and Y104.By greatly improving the single-well productivity and lifecycle,it helps increase the development benefit.Accordingly,the utilization degree of the tight oil in Shengli oil field has been improved economically and effectively.