岩石学报
巖石學報
암석학보
ACTA PETROLOGICA SINICA
2010年
1期
255-262
,共8页
构造应力场%构造裂缝%火山岩%数值模拟%有限元方法%准噶尔盆地
構造應力場%構造裂縫%火山巖%數值模擬%有限元方法%準噶爾盆地
구조응력장%구조렬봉%화산암%수치모의%유한원방법%준갈이분지
Structural stress field%Structural fracture%Volcanic rocks%Numerical simulation%Finite element method%Junggar Basin
构造裂缝的发育对改善储层的储渗条件有着重要的作用,特别是火山岩这种非传统储层,构造裂缝的发育是其成为有效储层的必要条件.本文主要借助构造应力场有限元数值模拟这一成熟的方法对准噶尔盆地石炭纪火山岩构造裂缝的发育状况进行预测.其两个主要的步骤是首先对区域构造应力场进行模拟计算,然后结合岩石的强度指标判断构造裂缝的发育状况.通过对准噶尔盆地地质背景和构造演化的分析,明确了新生代构造应力场的的决定性作用和石炭纪火山岩的分布区域(划分出六个区域),建立了数值模拟的计算模型、确定了边界条件与载荷.通过二维有限元数值模拟(应用Ansys软件)得到了新生代盆地应力场的分布特征和应力值.结合岩石强度指标,对火山岩构造裂缝(张裂缝和剪裂缝)的发育进行了预测并圈出相应的区域,主要为盆地西北缘、中央坳陷中部、滴西1东部,彩参2周缘、大井-将军庙等地区,对石炭纪火山岩的油气勘探战略选区,优化勘探部署具有重要指导意义.
構造裂縫的髮育對改善儲層的儲滲條件有著重要的作用,特彆是火山巖這種非傳統儲層,構造裂縫的髮育是其成為有效儲層的必要條件.本文主要藉助構造應力場有限元數值模擬這一成熟的方法對準噶爾盆地石炭紀火山巖構造裂縫的髮育狀況進行預測.其兩箇主要的步驟是首先對區域構造應力場進行模擬計算,然後結閤巖石的彊度指標判斷構造裂縫的髮育狀況.通過對準噶爾盆地地質揹景和構造縯化的分析,明確瞭新生代構造應力場的的決定性作用和石炭紀火山巖的分佈區域(劃分齣六箇區域),建立瞭數值模擬的計算模型、確定瞭邊界條件與載荷.通過二維有限元數值模擬(應用Ansys軟件)得到瞭新生代盆地應力場的分佈特徵和應力值.結閤巖石彊度指標,對火山巖構造裂縫(張裂縫和剪裂縫)的髮育進行瞭預測併圈齣相應的區域,主要為盆地西北緣、中央坳陷中部、滴西1東部,綵參2週緣、大井-將軍廟等地區,對石炭紀火山巖的油氣勘探戰略選區,優化勘探部署具有重要指導意義.
구조렬봉적발육대개선저층적저삼조건유착중요적작용,특별시화산암저충비전통저층,구조렬봉적발육시기성위유효저층적필요조건.본문주요차조구조응력장유한원수치모의저일성숙적방법대준갈이분지석탄기화산암구조렬봉적발육상황진행예측.기량개주요적보취시수선대구역구조응력장진행모의계산,연후결합암석적강도지표판단구조렬봉적발육상황.통과대준갈이분지지질배경화구조연화적분석,명학료신생대구조응력장적적결정성작용화석탄기화산암적분포구역(화분출륙개구역),건립료수치모의적계산모형、학정료변계조건여재하.통과이유유한원수치모의(응용Ansys연건)득도료신생대분지응력장적분포특정화응력치.결합암석강도지표,대화산암구조렬봉(장렬봉화전렬봉)적발육진행료예측병권출상응적구역,주요위분지서북연、중앙요함중부、적서1동부,채삼2주연、대정-장군묘등지구,대석탄기화산암적유기감탐전략선구,우화감탐부서구유중요지도의의.
Structural fractures can strongly upgrade the reservoir quality of rocks, which is essentially important for volcanic rocks, the unconventional reservoir type. Therefore, awareness of fracture development in those rocks becomes a key point to explore and develop these plays. Employing numerical simulation based on finite element method, the study predicts the development of Cenozoic structural fracture in Carboniferous volcanic rocks, Junggar Basin. Focusing on Cenozoic stress is due to that it is the newest and dominant stress stage imposed on Carboniferous volcanic rocks since its formation. The simulation model including the geometry, mechanical properties and the load conditions is built based on geological study of the basin and 6 areas (Ⅰ- V1 and V 2) of Carboniferous volcanic rocks are blocked out. Stress field is then calculated by employing Ansys 9.0 software and the values of shear stress and tensile stress are obtained. By comparing the stress value to the strength of rocks, tensile fractures and shear fractures are predicted respectively. Finally, potential development areas of structural fractures are marked out: Most part of V1 and V2, northern part of Ⅰ , northwestern of Ⅱ and eastern part of Ⅲ and Ⅳ. This would be helpful to the exploration and development of Carboniferous strata in the basin.