超高温高压气藏酸液有效作用距离定量研究  

QUANTITATIVE STUDY ON EFFECTIVE PENETRATION DISTANCE OF ACID FLUID IN ULTRA-HPHT GAS RESERVOIRS

作　　者：王洋 袁清芸 

机构地区：[1]中石化西北油田分公司石油工程技术研究院 [2]中石化西北油田分公司勘探开发研究院

出　　处：《钻采工艺》2016年第6期31-33,共3页Drilling & Production Technology

基　　金：国家"十二五"科技重大专项"缝洞型碳酸盐岩油藏高效酸压改造技术"(2011ZX05014-006)资助

摘　　要：顺南奥陶系气藏具有超深（6300～7800m）、超高温（187℃～205℃）、高有效闭合压力（60MPa）的特点，前期试采井自喷投产后无法获得持续高产，需通过深度酸压沟通远端储集体释放产能，超高温、超高压条件下酸液有效作用距离定量研究对酸压设计具有重要意义。采用高温高压酸化流动仪开展胶凝酸、转向酸和冻胶酸导流能力测试，根据酸溶蚀速率获得3种酸液的酸岩反应动力学方程，应用过酸前后导流能力结果计算3种酸液残酸浓度，界定地层条件酸岩反应有效时间，并定量计算不同浓度胶凝酸、转向酸和冻胶酸在顺南地层条件下酸液有效作用距离。实验得出，190℃、60MPa条件下，残酸浓度：冻胶酸〉胶凝酸〉转向酸。酸液有效作用时间：转向酸〉冻胶酸〉胶凝酸；酸液有效作用距离：转向酸〉冻胶酸〉胶凝酸。研究结果表明，相比胶凝酸和冻胶酸，转向酸在顺南超高温、超高压条件下具有更好的深穿透造缝能力。The Ordovician gas reservoir in Shunnan has features of ultra-deep burial(6 300 ~7 800 m),ultra-high temperature(187℃ ~ 205℃) and high effective closure pressure(60 MPa).The trial-production well at early stage could not get persistent high production rate without releasing productivity by communicating distant reservoir bodies through in-depth acid fracturing.Therefore,the quantitative study on effective acting distance of acid fluid under the condition of ultra-temperature and ultra-pressure is significant for acid fracturing design.HPHT acid flow tester was used to test the flow conductivity of gelled acid,diversion acid and cross-lined acid.The kinetics equation of acid-rock reaction was then set up based on the erosion rate of those acids.And the spent acid concentration could be calculated by using the flow conductivity before and after acidizing,the effective acid-rock reaction time under formation condition could be defined,and finally the effective penetration distances of different acids at different concentrations under Shunnan formation condition were calculated.The test showed that under the condition of 190℃ and 60 MPa,reacted acid concentration was cross-lined acid(2.38%) > gelled acid,(1.98%) > Diversion acid(0.95%),the effective time was diversion acid(5.5 ~ 30 min) > cross-lined acid(9.8 — 19.2min) > gelled acid(2.7 ~ 11.8 min),the effective penetration distance was diversion acid(24.9 ~ 139.25 m) > cross-lined acid(56~83 m) > gelled acid(11.3 ~51.6 m).Those proved that diversion acid was superior to the other acids in creating deeper penetration at ultra-HPHT formations at Shunnan,which would provide a theoretical basis for optimum acid frac design in Shunnan gas reservoir.

关 键 词：超高温 残酸浓度 有效作用时间 有效作用距离 

分 类 号：TE37[石油与天然气工程—油气田开发工程]