四川盆地元坝地区陆相储层高破裂压力成因与技术对策  

Technological strategies for and causes of high fracture pressure of continental reservoirs in the Yuanba Gas Field,Sichuan Basin

作　　者：蒲洪江[1] 何兴贵[2] 黄霞[2] 

机构地区：[1]中国石化西南油气分公司 [2]中国石化西南石油工程有限公司

出　　处：《天然气工业》2014年第7期65-70,共6页Natural Gas Industry

摘　　要：四川盆地元坝地区处于强应力场环境中,其陆相储层破裂压力梯度为0.026~0.037 MPa/m,已成为制约该区完井、储层压裂改造效果的主要技术难题。为此,在深入研究储层高破裂压力的地质成因和工程作用对破裂压力影响的基础上,探索试验了降低施工作业井口压力的技术措施和方法：以近最大水平主应力方向作为射孔方位,同时采用长井段、大孔径、高孔密、深穿透射孔（含喷砂射孔、补充射孔）来降低压裂造缝压力;采用酸损伤（酸泡、酸洗）技术来解除储层污染和降低岩石强度;采用加重酸液增加液柱压力和大内径管柱配合低阻性酸液或压裂液体系以降低施工摩阻。现场应用实践表明,单独或组合采用这些工艺技术措施,就能有效地降低施工作业的井口压力,实现储层酸压或加砂压裂改造作业。该试验研究成果可供类似地区借鉴。Because the Yuanba Gas Field in the Sichuan Basin is situated in a strong stress field, the fracture pressure gradient of continental reservoir is as high as up to 0.026 - 0.037 MPa/m, technically restricting the completion and reservoir fracturing quality. On the basis of an intensive study of geological causes of high fracture pressure and the impact of engineering work on fracture pressure, the following technical measures and methods were developed and tested to reduce wellhead pressure in operation： take nearly maxi- mum horizontal principal stress direction as perforation orientation and adopt long interval, large bore diameter, high shooting density, and deep-penetrating perforating （including abrasive perforating and supplementary perforating） to reduce the width generation pressure; use the acidic injury （acid sinking and pickling） technology to eliminate reservoir pollution and reduce rock strength; add acid fluid to increase liquid column pressure, and use bigger string plus low-resistance acid fluid or fracturing fluid to reduce operating friction. Field application showed that the wellhead pressure can be effectively reduced by individual or combined aforementioned measures to achieve the acid fracturing or sand fracturing of the reservoir. The test results are also applicable to similar areas .

关 键 词：四川盆地 元坝地区 陆相储集层 高破裂压力 裂缝 污染 射孔参数 技术对策 

分 类 号：TE31[石油与天然气工程—油气田开发工程] TE357