SF气田蓬莱镇组气藏压裂伤害机理分析及工艺对策  

Fracturing Damage Mechanisms and Their Countermeasures for Penglaizhen Gas Reservoir, SF Gasfield

作　　者：刘林[1] 黄禹忠[1] 刁素[1] 栗铁峰[1] 

机构地区：[1]中国石化西南油气分公司工程技术研究院,四川德阳618000

出　　处：《天然气技术与经济》2015年第5期24-26,78,共3页Natural Gas Technology and Economy

基　　金：国家科技重大攻关专项<大型油气田及煤层气开发>(编号:2011ZX05002)下设专题<四川盆地低渗气藏储层改造工艺技术研究>(编号:2011ZX05002-004-003)的部分研究内容

摘　　要：针对SF气田蓬莱镇组气藏储层压后产量低的问题,通过对储层的微观特征和渗流机理的研究,认识到粒间孔被伊蒙混层、绿泥石等充填是储层水敏的根本原因,孔喉细小,毛管自吸在短时间(24 h)内能达到较高含水饱和度(45%以上),使储层渗透率明显降低,造成较为严重的水相圈闭损害,从而影响了压后天然气产量。针对伤害机理,采用了减少水敏、降低毛管力和界面张力的防膨防水锁压裂液,提出了减少入地液量和施工时间的脉冲柱塞加砂压裂工艺、液氮伴注提高返排速率的降低储层含水饱和度的工艺对策,现场应用36井次,压后16 h平均返排率达到62.5%,平均测试产量3.3×104m3/d,较前期平均测试产量1.2×104m3/d提高了166%。There is a problem of low post-frac production exising in Penglaizhen gas reservoir, SF gasfield. So, after a research on its microscopic features and percolation mechanism, it is found(1)that intergranular pore is filled with illite- montmorillonite mixed layer and chlorite is the root cause of water sensitivity; and(2) with tiny pore throat and capillary imbibition, water saturation can achieve a higher level(>45%) in a short time(24 h), resulting in significantly reducing permeability and serious water phase trapping damage. These two findings may affect the post-frac gas production. According to damage mechanisms, a kind of fracturing fluid with anti-swelling and anti-water-blocking performance was adopted to decrease water sensitivity, capillary force, and interfacial tension. Also, two technological countermeasures were put forward:pulse piston sand fracturing technology with reducing fluid volume injected and construction time; water-saturation reduction technology with increasing flowback rate by liquid nitrogen injection. Their application to 36 well times indicates that at 16 hours after fracturing, the average flowback rate reaches 62.5% and the average testing production achieves 3.3×104m3/d, respectively. Compared with the previous average testing production of 1.2×104m3/d, it increases by 166 %.

关 键 词：水敏 水相圈闭 伤害机理 脉冲柱塞加砂 液氮伴注 

分 类 号：P618.13[天文地球—矿床学]