地质学报2017，Vol.91Issue(11)：2557-2572,16.
塔里木盆地大北气田构造应力场解析与数值模拟
Analysis and Numerical Simulation of Tectonic Stress Field in the Dabei Gas Field, Tarim Basin
摘要
Abstract
Study of tectonic stress field has theoretical and practical significance to understanding the development of the Dabei gas field in the Tarim Basin.Directions of paleo-and present tectonic stress fields were determined using the strikes of regional fault and anticline's long axis,trends of drilling induced fracture,and borehole breakout orientation.The magnitude of the tectonic stress was also calculated using well logging data.Based on above,geological models of Dabei 102 Block and Dabei 201 Block in the main gas pools of the Dabei gas field were established by ANSYS,a finite element modeling (FEM) software.Rock mechanical parameters were obtained through well logging data calculation and dynamic-static conversion.And boundary condition was determined by tectonic stress field analysis results.Numerical simulation of paleo-and present tectonic stress field of the Dabei gas field was finally performed to analyze the distribution regularity of tectonic stress field and the relationship between tectonic stress field and structural fracture and well capacity.The results show that the directions of paleo-and present maximum horizontal principal stresses of the Dabei gas field are about NNW336° and NWW305° respectively,and the magnitudes of stresses are characteristic of σH ＞σh ＞σv (Type Ⅱ) of paleo-stress and σH ＞σv ＞σh (Type Ⅲ) of present stress,suggesting that they belong to type Ⅱ and type Ⅲ stresses.The values of principal stresses and deviator stress are horizontally low at the high spots of anticline and high on the limbs,and increase with the increasing depth vertically.Strike of structural fractures is controlled by the direction of horizontal maximum paleo-tectonic stress,and it is nearly parallel to or intersects in small angle with the direction of the present horizontal maximum principal stress.In this case,structural fractures can extend continuously along their strikes,and the aperture will not reduce dramatically as the tectonic compression,and therefore the validity of structural fractures can be well preserved.Development extent of structural fractures in gas pools is in positive correlation with deviator stress.The high spot of an anticline corresponds to the low value zone of tectonic stress,thus hydrocarbon tends to accumulate to form reservoir under the driving of stress potential difference and buoyancy.The wells with high deviator stress have higher development extent of structural fracture and therefore higher open flow capacity.Thus there will be a high probability to yield high production of natural gas if wells are deployed at the high spots of an anticline where have high deviator stress.关键词
构造应力场/有限元/数值模拟/构造裂缝/产能/大北气田Key words
tectonic stress field/finite elements/numerical simulation/structural fracture/capacity/Dabei gas field引用本文复制引用
王珂,张惠良,张荣虎,王俊鹏,刘春,杨学君..塔里木盆地大北气田构造应力场解析与数值模拟[J].地质学报,2017,91(11):2557-2572,16.基金项目
本文为国家科技重大专项(编号2016ZX05003-001-002、2016ZX05001-002-003)资助的成果. （编号2016ZX05003-001-002、2016ZX05001-002-003）
