胜利油田滩浅海裂缝型油藏固井技术

Cementing Technology of Shallow Sea Buried Hill Reservoir in Shengli Oilfield

针对胜利油田滩浅海潜山油藏埋藏深、温度高、地层承压能力低、漏失风险大、尾管重叠段密封完整性差、临井长期反复酸压造成的钻井过程出酸等难题,改进完善了膨胀尾管悬挂器,密封组件采用氟橡胶与软金属结合,耐温达到250℃以上,密封压力>35MPa,有效保证了喇叭口的有效密封;优选不锈钢整体式弹性扶正器,有效避免了酸液对扶正器的破坏,保证小间隙工况尾管下入能力及套管居中程度;同时,基于紧密堆积理论,研发了1.35~1.45g/cm^(3)具有防窜功能的耐高温高强低密度水泥浆体系,降低了漏失风险,提高了封固质量。在胜利油田ZG及CB区块成功应用,固井合格率100%,形成了适用于胜利油田的滩浅海裂缝型油藏固井技术。

Aiming at the problems of deep burial,high temperature,low formation pressure,high risk of leakage,poor seal integrity of the liner overlapping section,and acid production during drilling caused by long-term repeated acid fracturing in Shengli Oilfield,improved the expansion liner hanger,sealing components are combined with fluorine rubber and soft metal,the temperature resistance is above 250℃,and the sealing pressure is more than 45MPa,which effectively guarantees the effective sealing of the bell mouth;the stainless steel integral elastic centralizer is preferably used to effectively avoid the damage of the centralizer by the acid.The running capacity of the tailpipe and the centering degree of the casing in small clearance conditions;at the same time,based on the tight packing theory,a high-temperature,highstrength,low-density cement slurry system with anti-channeling function of 1.35~1.45g/cm3 has been developed to reduce the risk of leakage and improve the sealing quality.It has been successfully applied in the Zhuanggu and Chengbei blocks of Shengli Oilfield,with a cementing qualification rate of 100%,forming a cementing technology suitable for shallow sea fractured reservoirs in Shengli Oilfield.