摘要
南海西部莺琼盆地高压低渗地层广泛发育,低渗高压地层在欠比重条件下开泵状态时可能不会有溢流,甚至关井时短时间内也没有套压,造成已经压稳地层的假象,而循环气测却比较高,单根气明显,在起钻中途发现灌浆困难出现溢流。另外高温高压井通常压力窗口窄,在低比重揭开高压低渗地层时,时常会出现提比重至没有作业窗口后还没有压稳地层的情况,继续提比重有漏失风险,起钻进行下一步作业则有井控风险。针对以上难题,本文总结了低渗地层现场摸索压力的方法,同时总结了低渗高压地层在没有完全压稳且没有窗口提比重的前提下能否起钻进行下步作业的评估方法,为类似作业提供了参考。
High-pressure and low-permeability strata are widely developed in the Yingqiong Basin in the western South China Sea.The low-permeability and high-pressure strata may not overflow when the pump is turned on under conditions of low specific gravity.There may even be no casing pressure for a short period of time when the pump is shut down,resulting in the formation of stabilized strata.The circulating gas measurement was relatively high,and the gas in a single pipe was obvious.During the drilling process,it was found that grouting was difficult and overflow occurred.In addition,high-temperature and high-pressure wells usually have narrow pressure windows.When the high-pressure and low-permeability formations are exposed at low specific gravity,it often happens that the formation has not been stabilized after increasing the specific gravity until there is no operating window.If the specific gravity is continued to increase,there is a risk of leakage,and the drilling proceeds to the next step.Operations involve well control risks.Point at the above problems,this article summarizes the method offield exploration of pressure in low-permeability formations,and also summarizes the evaluation method of whether low-permeability and high-pressure formations can be drilled for further operations without complete pressure stabilization and without a window to increase the specific gravity.
作者
贾轲
Jia Ke(CNOOC Energy Technology&Services Limited Zhanjiang Branch,Zhanjiang 524000)
出处
《石化技术》
CAS
2024年第3期109-111,共3页
Petrochemical Industry Technology
关键词
高压低渗地层
窄压力窗口
压力摸索
起钻评估
High pressure and low permeability formation
narrow pressure window
Pressure groping
Trimming evaluation
