摘要
非常规页岩油气的开发对于保障我国能源安全具有重要意义,在我国页岩油气水力压裂开采过程中,套管变形问题十分突出,严重制约了我国页岩油气的高效开发。大港官东页岩油区块进行压裂作业后,套管变形问题严重,初期套变率高达66%。对比官东页岩油区块的断层位置信息后发现套管的变形区域与井眼轨迹和断层交点位置重叠度较高,表明套管变形问题与压裂过程中的断层运动关系密切。通过MIT(The Multi Finger Imaging Tool)工具对套管变形区域进行了测量,所得的数据基于SolidWorks软件重构了变形套管的3D形貌,结果显示,套管的变形特征与断层的运动方向和视图观察方向有关剪切变形,并不一定呈现出经典S型变形特征。该地区的套管主要受水平方向运动的走滑断层挤压,平行断层错动方向可观察到套管截面存在受压扩径的特征。为了研究断层错动对套管内部受力的影响,本文用Abaqus软件建立了含断层的地层—水泥环—套管模型,并通过控制位移边界条件模拟了走滑断层的运动,且对不同的断层倾角和走向造成的套管局部受力变化进行了敏感性分析。研究结果表明:(1)受断层剪切的套管变形特征与观察方向有关,平行断层运动方向观察套管形貌应观察到受压膨胀的特征,垂直断层运动方向观察套管形貌,应观察到S型的剪切变形特征;(2)套管受断层挤压影响,在变形区域的截面轮廓则会呈现出椭圆化的特征,套管的受挤压方向和截面的短轴方向一致;(3)水平运动的断层,其倾角越大,套管达到极限强度时的位移越小;目标区块地应力条件下,断层走向为45°时套管达到极限强度时的位移最小。研究结果为确定套管变形是否由断层滑移造成提供了判断依据。
The development of unconventional shale oil and gas is of great significance for ensuring China’s energy security. In the process of shale oil and gas hydraulic fracturing in China, casing deformation is very serious, which restricts the development of shale oil and gas in China. After fracturing operation in Dagang Guandong Shale Oil Block, the casing deformation rate was 66%. After analyzed the fault data of the Guandong shale oil block, it was found that the casing deformation area had a high overlap with the well trajectory and fault intersection, which indicated that the casing deformation is closely related to the fault slip during fracturing. The deformation area of the casing was measured by the MIT(The Multi Finger Imaging Tool) tool, and the obtained data were inversed based on the SolidWorks software to obtain the deformed casing 3D model. The analysis results of the deformation characteristics of the model showed that the deformation characteristics of the casing are strongly related to the movement direction of the fault and the direction of observation, and it does not always show the classic S-shaped deformation characteristics.The casing in this area is mainly squeezed by the strike slip fault moving in the horizontal direction, so the casing section can be observed to be compressed and expanded in the vertical fault dislocation direction. To study the influence of fault shearing on the casing, a formation-cement sheath-casing model(containing fault) was established by using Abaqus software, and the fault slip was simulated by controlling the displacement boundary conditions, and the sensitivity analysis of geo stress changes of casing caused by different fault dip angles and strike were carried out. The research results showed that:(1) The deformation characteristics of the casing are related to the observation direction. When the observing direction paralleled to the fault movement direction, the compression expansion characteristics could be observed;When the observing direction perpendicular
作者
闫伟
王孔阳
邓金根
唐庆
步宏光
檀朝东
阴启武
秦飞翔
YAN Wei;WANG Kongyang;DENG Jingen;TANG Qing;BU Hongguang;TAN Chongdong;YIN Qiwu;QIN Feixiang(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum-Beijing,Beijing 102249,China;Oil Production Technology Research Institute,PetroChina Dagang Oilfield Company,Tianjin 300280;Petroleum Engineering Research Institute,Petrochina Dagang Oilfield Company,Tianjin 300280)
出处
《石油科学通报》
2022年第4期543-554,共12页
Petroleum Science Bulletin
基金
国家自然科学基金面上项目“页岩储层多级压裂诱导应力累积对套管变形的影响机制研究”(编号:52274015)
中南大学有色金属成矿预测教育部重点实验室开放基金“压裂液与致密砂岩的相互作用及其对缝网形成的影响”(编号:2019YSJS06)联合资助。
关键词
官东地区
页岩油
水力压裂
套管变形
MIT测量
断层滑移
Guandong oil field
shale oil
hydraulic fracturing
casing deformation
MIT measurement
fault slip
