摘要
准噶尔盆地高闭合应力致密储层是指井深大于3 500 m,闭合应力梯度大于0.02 MPa/m,且由于储层物性差、杨氏模量高、泊松比高,导致地层破裂压力高而难以压开的储层,主要包括西北缘二叠系、车排子凸起侏罗系和白垩系及部分高温超深风险探井钻遇的储层。目前对此类储层改造的重点与难点主要体现在5个方面:①施工风险大、技术选择余地小;②施工易砂堵;③对压裂材料的性能要求高;④微裂缝发育,压裂液滤失严重;⑤设备故障率较高。通过现场实践与研究,形成了以降低井口施工压力技术为核心,支撑剂组合优化技术与施工参数优化技术相结合的高闭合应力致密储层改造技术体系,加重压裂液密度最高达1.365 g/m3,突破了技术瓶颈,使高闭合应力致密储层探井压裂成功率由常规方法的50%提高至100%。
The tight reservoir with high closure stress in Junggar basin refers to the ones whose depth exceeds 3 500 m and closurestress gradient higher than 0.02 MPa/m,which is characterized by poor reservoir physical properties,high Young's modulus and Poisson's ratio,and therefore leading to high fracture pressure.The typical reservoirs in Junggar basin mainly includes the Permian reser-voirs in northwestern margin of Chepaizi uplift,Jurassic and the Cretaceous reservoirs and the ones penetrated by some risk explorationwells.There are many difficulties about the reservoirs: very high wellhead pressure,easy to form complex fractures because of naturalfractures,proppant bridge because of the narrow fractures,high risk because of long time and high slurry rate,and so on.This paperpresents 3 technologies: wellhead pump pressure reduction technology,proppant optimization technology and parameters optimizationtechnology.These technologies can increase the well fracturing success rate of tight reservoirs from 50% to 100%.It has provided tech-nical supports for the tight reservoir exploration and development of Junggar basin.
出处
《油气地质与采收率》
CAS
CSCD
北大核心
2014年第2期98-101,117-118,共4页
Petroleum Geology and Recovery Efficiency
基金
中国石油油气勘探重点工程技术攻关项目"准噶尔盆地复杂岩性低渗储层试油(含措施改造)配套技术研究"
关键词
高闭合应力
致密储层
储层改造
加重压裂液
延迟交联
酸化预处理
high closure stress
tight reservoir
reservoir stimulation
weighted fracturing fluid
delayed crosslink
acidizing pretreatment
