摘要
针对致密碳酸盐岩气藏难以获得高产、稳产这一难题,借鉴国外页岩气体积改造理念,对鄂尔多斯盆地下古生界致密碳酸盐岩气藏体积酸压可行性进行分析。首先阐述了致密碳酸盐岩气藏体积酸压的增产机理,在此基础上,从储层可压裂性、天然裂缝发育状况、水平主应力差、水力裂缝与天然裂缝夹角4个方面分析了体积酸压在致密碳酸盐岩气藏开发中的优势及其局限性,并针对技术局限性提出了相应的改造策略。研究结果表明,体积酸压可形成复杂的裂缝网络,获得较大的储层改造体积;其增产改造效果与储层中的岩石可压裂性、天然裂缝发育状况及天然裂缝与水力裂缝的夹角密切相关,较大水平主应力差会对裂缝网络的形成产生不利影响,可通过可降解纤维暂堵转向技术或转向酸酸压来弱化甚至消除该影响。先导试验结果表明,18口井体积酸压后比邻近常规酸压井增产60%以上,1个月后,其中7口井的日产气量比常规酸压井高41%以上,说明体积酸压比常规酸压在鄂尔多斯盆地下古生界碳酸盐岩气藏中具有更好的增产效果和较好的应用前景。
Aimed at the difficulty of achieving high and stable production in the tight carbonate gas reservoir,the feasibilityof volume acid fracturing to lower Paleozoic tight carbonate gas reservoir in Ordos basin was analyzed with reference to thevolume fracturing for shale gas in foreign countries. Firstly,stimulation mechanism of the volume acid fracturing in the tightcarbonate gas reservoir was introduced. Based on this,the advantage and limitation of the volume acid fracturing for the development of the tight carbonate gas reservoir were analyzed on reservoir fracturing probability,natural fracture development,horizontal principal stress difference,intersection angle of natural fracture and hydraulic fracture,and the solution forthe limitation was put forward. The study results show that the volume acid fracturing can form complex fracture network,and gain larger stimulated volume of reservoir. The stimulation effect of the volume acid fracturing is closely related to thereservoir fracturing probability,natural fracture development,intersection angle of natural fracture and hydraulic fracture.The large horizontal principal stress difference will has disadvantage impact on the fracture network formation,which maybe removed by the degradable fiber diversion technology or self-diverting acid fracturing. The results of pilot test indicatethat gas production of 18 gas wells after volume acid fracturing exceed that of adjacent gas wells of conventional acid fracturing by more than 60%,and the daily gas production of volume acid fracturing in 7 wells exceed that of conventional acidfracturing by more than 41% after one month. It shows that stimulation effect of the volume acid fracturing is better thanthat of the conventional acid fracturing for lower Paleozoic carbonate gas reservoir in Ordos basin,and the volume acid fracturing has a good prospect of application in future.
出处
《油气地质与采收率》
CAS
CSCD
北大核心
2016年第3期120-126,共7页
Petroleum Geology and Recovery Efficiency
基金
国家科技重大专项"鄂尔多斯盆地大型低渗透岩性地层油气藏开发示范工程"(2011ZX05044)
国家自然科学基金项目"复杂非均质碳酸盐岩储层水平井酸化高效布酸基础理论研究"(51474182)
关键词
致密油气
致密碳酸盐岩
体积酸压
裂缝网络
储层改造体积
鄂尔多斯盆地
tight oil and gas
tight carbonate rock
volume acid fracturing
fracture network
stimulated reservoir volume
Ordos basin
