摘要
以镇泾油田长8组砂岩油层为研究对象,探讨了压裂液损害评价方法,并进行压裂液滤液对基块岩样渗透率损害率和压裂破胶液动态滤失对造缝岩样返排恢复率测定的压裂液动态损害实验;考察了压裂液与地层流体、工作液之间的配伍性,压裂液和原油的润湿性,测定了压裂液乳化率和残渣。压裂液原胶液组成为0.4%HPG(瓜尔胶)+0.4%AS-6(季铵盐类黏土稳定剂)+0.3%CX-307(阴离子型破乳助排剂)+0.1%HCHO(杀茵剂)。实验结果表明,原油与破胶液按3:1、3:2、1:1体积比混合后的乳化率均在60%以上,而破乳率仅为12.00%～23.77%。压裂液残渣含量平均为703 mg/L,易阻塞储层渗流通道。裂缝岩样经压裂液驱替后的返排恢复率为1.48%～85.83%;当裂缝充填支撑剂后的返排恢复率为0.02%～42.9%,较单纯裂缝岩样低。基块岩样压裂液乳化损害程度强,平均损害率为89.83%;残渣液损害程度强,平均损害率为73.71%;压裂液滤液损害程度中等偏弱,平均损害率为44.85%。压裂液产生的润湿反转使岩石由水湿转化为油湿。固相侵入、碱敏、润湿反转是储层损害的主要因素。固相侵入的损害率为28.86%,润湿性相关的损害率为44.98%,基块岩样碱敏损害率26.38%、裂缝岩样为32.18%。建议采用清洁压裂降低残渣损害、选用合适的表面活性荆提高返排率,为该油田储层保护和有效开发提供支持。
Dealing with the study of Chang-8 oilfield group sandstone reservoir, the damage evaluation of fracturing fluid was discussed, and two experiment evaluations of dynamic damage for fracturing fluid were conducted, including the permeability damage of fracturing fluid filtrate for sample rock, and the dynamic filtration of fracturing gel breaking liquid for the flow back rate measurement of fracture-making rock. At the same time, several related experiment evaluations of static damage for fracturing fluid were finished, such as the compatibility between fracturing fluid and formation fluid or working fluid, the wettability between fracturing fluid and crude oil, the emulsification rate and the residue. The formula of fracturing fluid was 0.4% HPG（guar gum）＋ 0.4% AS-6 （clay stabilizer）＋ 0.3% CX-307 （demulsify-cleanup additive）＋ 0.1% HCHO （microbicide）. The experiment results showed that the emulsifying rates were more than 60% when the volume ratios of oil and gel breaking liquid were of 3：1, 3：2, 1：1, and the emulsion breaking rates were only 12.00%--23.77%. The average content of fracturing fluid residue was of 703 mg/L, and the throat was easily blocked. The flow back recovery rate of fracturing rock was of 1.48%--85.83%, and that was only 0.02%-- 42.9% when the fractures were supported by proppant. The emulsification damage of basic rock for fracturing fluid was strong with 89.83% average damage rate. The damage of liquid residual was strong with 73.71% average damage rate. The damage of fracturing fluid filtrate was medium-low with 44.85% average damage rate. The wettability of rock reversal from water-wet into oil-wet had been generated by fracturing fluid. The solid-phase invasion, alkali sensitivity and wettability reversal were the main factors of reservoir damage. The damage rate of solid phase intrusion was of 28.86%, that of wettability was of 44.98%, and that of alkali-sensitive for basic rock and fracturing rock was of 26.38% and 32.18%, respectively. It was suggested that u
出处
《油田化学》
CAS
CSCD
北大核心
2013年第2期173-178,共6页
Oilfield Chemistry
基金
国家重点基础研究发展计划(973计划)"深井复杂地层漏失及井壁失稳机理及预测"(项目编号2010CB226705)
国家重大专项"页岩气层工程作业适应性及储层保护对策研究"(项目编号2011ZX05005-006-008HZ)
关键词
特低渗透油藏
储层保护
储层损害
压裂液
镇泾油田
extra-low permeability reservoir
reservoir protection
reservoir damage
fracturing fluids
Zhenjing oil fields
