四川盆地下寒武统龙王庙组气藏转向酸酸化模拟及其应用

发布时间：2018-09-18 12:14

【摘要】：四川盆地下寒武统龙王庙组气藏白云岩储层溶蚀孔洞、天然微裂缝均发育,储层较强的非均质性和严重的钻完井液伤害导致均匀布酸困难,特别是对于长井段大斜度井和水平井酸化改造则更加困难。为此,从黏弹性表面活性剂转向酸转向变黏机理和流变行为研究入手,优选转向性能好且二次伤害低的转向酸作为主体酸液,根据流变行为实验结果拟合有效黏度经验模型,耦合双尺度蚓孔扩展模型,建立自转向酸酸化数学模型,模拟长井段大斜度井非均匀伤害下转向酸酸化的pH值、Ca~(2+)浓度、有效黏度和蚓孔形态等,并对比了胶凝酸和5%VES转向酸酸化的蚓孔形态、流量分配和吸酸剖面。结果表明:转向酸可明显地改善强非均质性储层的吸酸剖面,增强对低渗透储层的改造力度。针对该盆地龙王庙组白云岩储层强非均质性和钻完井液伤害复杂性,形成了长井段割缝衬管完成大斜度井和水平井变VES浓度转向酸酸液置放技术,现场应用8井次,累计获井口测试天然气产量1 233.46×10~4m~3/d,平均单井增产倍比达到1.95,该技术有力地支撑了对龙王庙组特大型气藏的高效开发。
[Abstract]:In the Lower Cambrian Longwangmiao formation gas reservoir of Sichuan Basin, the dolomite reservoir is corroded, the natural microfractures are all developed, the strong heterogeneity of the reservoir and the serious damage of drilling and completion fluid lead to the difficulty of even acid distribution. It is more difficult to acidify long well section and horizontal well. Therefore, based on the study of the mechanism and rheological behavior of turning from viscoelastic surfactant to acid, the steering acid with good performance and low secondary damage was selected as the main acid solution. The empirical model of effective viscosity was fitted according to the experimental results of rheological behavior. Coupled with the two-scale wormhole expansion model, a self-turning acidating mathematical model was established to simulate the concentration of Ca ~ (2), the effective viscosity and the morphology of the wormhole in the non-uniform damage of the large-slope well of the long well, and the concentration of Ca ~ (2), the effective viscosity, and the morphology of the wormhole, etc. The morphology, flow distribution and acid-absorption profile of the vermis pore in the conversion from gelling acid to acid by 5%VES were compared. The results show that the acid absorption profile of strong heterogeneity reservoir can be improved obviously and the transformation of low permeability reservoir can be enhanced. In view of the strong heterogeneity of dolomite reservoir in Longwangmiao formation in this basin and the complexity of drilling and completion fluid damage, the technology of changing VES concentration to acid liquid placement in long well section and horizontal well is formed. The cumulative well head test of natural gas production is 1 233.46 脳 10 ~ (4) m ~ (-1) / d, and the average ratio of increasing the output per well is 1.95. This technique can support the high efficiency development of the super-large gas reservoir in Longwangmiao formation.
【作者单位】：中国石油西南油气田公司;中国石油西南油气田公司工程技术研究院;振华石油控股有限公司;成都北方石油勘探开发技术有限公司;四川页岩气勘探开发有限责任公司;
【基金】：国家科技重大专项“大型油气田及煤层气开发:四川盆地大型碳酸盐岩气田开发示范工程”(编号:2016ZX05052) 中国石油天然气集团公司重大科技专项“四川盆地深层高温高压含硫气藏储层改造技术研究与应用”(编号:2016E-0609)
【分类号】：TE357.2

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