摘要
泥岩具有极强吸水性能,泥岩水化膨胀将会使套管服役环境恶化,降低套管使用寿命。为研究不同驱替液水化泥岩层后对套管服役的影响,首先针对目的区块泥岩进行组分、水化膨胀及力学实验,并在此基础上建立不同水化膨胀工况泥岩层的有限元模型,分析泥岩层水化膨胀对套管外挤载荷和套管应力变形影响。研究结果表明:泥岩层理发育,吸水后岩石易分散,聚合物化学液对泥岩水化作用相对更弱;泥岩水化后岩石强度降低,纯水和聚合物化学液浸泡后岩石强度分别降低为原样的1/20~1/15和1/3~1/2;泥岩水化膨胀增加了水化岩层段的套管外挤载荷和套管应力,与注纯水相比,注化学液可以降低套管外挤载荷和应力水平,对保护套管和延长套管使用寿命更加有利。
Mudstone has extremely strong water absorptivity,and its hydration swelling can deteriorate casing’s service environment and reduce its service life.In order to investigate the influences on the service of casing after mudstone is hydrated with different displacement fluids,this paper firstly carried out composition,hydration swelling and mechanic experiments on the mudstone of the target block.Then,the finite element model for the mudstone under different working conditions of hydration swelling was established.Finally,the influences of mudstone’s hydration swelling on casing’s external collapse load and strain were analyzed.It is indicated that the mudstone bedding is developed and the rocks tend to disperse after absorbing water,while polymer chemical solution has weaker influence on mudstone hydration.After mudstone is hydrated,its rock strength decreases.After it is immersed in pure water and polymer chemical solution,the rock strength is reduced by 1/20~1/15 and 1/3~1/2,respectively.Mudstone’s hydration swelling leads to the increase of casing’s external collapse load and stress in hydrated intervals.Compared with pure water injection,chemical solution injection can reduce casing’s external collapse load and stress,which is more beneficial to protect casing and prolong its service life.
作者
林铁军
周俊泽
练章华
易勇刚
于浩
王盛坤
LIN Tiejun;ZHOU Junze;LIAN Zhanghua;YI Yonggang;YU Hao;WANG Shengkun(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(Southwest Petroleum University),Chengdu 610500,Sichuan,China;Research Institute of Engineering Technology,PetroChina Xinjiang Oilfield Company,Karamay 834000,Xinjiang,China)
出处
《石油钻采工艺》
CAS
北大核心
2020年第6期784-790,共7页
Oil Drilling & Production Technology
基金
国家自然科学基金“超深井高强度油套管钢环境断裂的细观力学参数表征研究”(编号:51504207)。
关键词
泥岩
水化膨胀
套管
外挤载荷
有限元
mudstone
hydration swelling
casing
external collapse load
finite element
