微泡暂堵封窜技术研究与现场应用
Study and Application of Micro Bubble Temporary Plugging Technology
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摘要: 为了解决水泥封窜污染严重和颗粒型暂堵剂暂堵封窜有效期短的问题,研究应用了微泡暂堵封窜技术。通过室内试验评价了微泡工作液的剪切稀释性、静态堵漏性能、动态污染返排性能,结果表明:微泡工作液具有一定的剪切稀释性;封堵能力强,在120℃、0.5 MPa回压、5 MPa压差条件下,漏失量为0;返排性能好,对储层伤害小,微泡工作液污染48 h岩心的渗透率恢复率达到96.1%。冀东油田4口油井应用微泡暂堵封窜技术进行封窜,施工时泵压可控,施工后累计增油10 314 t,含水率平均降低17.6%,降水增油效果非常明显。这表明利用微泡暂堵封窜技术封窜施工风险小,封窜效果好,油层保护效果好,有效期长。Abstract: The conventional method to plug channeling with cement is apt to pollute formation,and particle-type temporary blocking agents usually have short effective period.We tried to solve the two problems with micro bubble temporary plugging.The properties(shear thinning behaviors,static plugging,dynamic pollution and flow back)of micro bubble treatment fluid were evaluated by lab experiment.The results proved that the micro bubble treatment fluid had certain shear thinning behavoir,and strong plugging ability.At the temperature of 120℃,back pressure of 0.5 MPa and differential pressure of 5 MPa,the leakage of the fluid was 0.It had good flow back ability,and caused little damage to reservoir.Core permeability recovery ratio was up to 96.1% after pollution by it for forty-eight hours.The technology has been used on four wells in Jidong Oilfield.The working pressure was controllable during injection of micro bubble plugging fluid.The treatment resulted in a cumulative oil increment of 10 314 t,and the average water cut had declined by 17.6%,the effects of increasing oil production and reducing aquifer yield were obvious.Its application indicated that it had low operation risk,strong plugging ability,good reservoir protection effect,and long period of validity.