川中龙王庙组储层成岩作用、孔隙和流体性质的时空变化

传统的储层成岩作用和孔隙演化研究，基本上无法预测储层性质在空间上的变化。拟选择川中高石梯-磨溪地区下寒武统龙王庙组储层为研究对象，选取一由露头、探井连接而成的剖面，横跨多沉积亚相，在微相和层序进一步划分的基础上，观察成岩作用现象、确定成岩作用相对序列、表征成岩流体地球化学。研究同一期胶结物或脉体古流体化学和同位素组成随空间的变化规律，确定古流体流动方向，查明储层孔隙度在空间上随沉积微相、流体流动方向，时间上随向上变浅沉积旋回、不同期次古流体地球化学组成的变化特征。建立古大气水溶蚀作用、深埋溶蚀作用的识别标志，评估现今孔隙究竟是油气侵位等作用抑制胶结和压溶作用而保存下来的，还是深埋条件下矿物溶解的产物，论证气藏是否发生热化学硫酸盐还原作用，阐明深埋条件下的矿物溶解作用机理，查明储层孔隙度随空间和时间变化的原因，建立优质储层发育模式。

Basically, spatial variation in reservoir property cannot be predicted using traditional methods to study reservoir diagenesis and porosity evolution. A section crossing different sub-facies from Lower Cambrian Longwangmiao Formation carbonate reservoirs from outcrops and wells in Gaoshiti-Moxi area, Middle Sichuan Basin was chosen as the study target. The following study will be carried out: 1) to firstly determine microfacies, sequence stratigraphy and diagenesis, to show spatial variation in paleo-fluid geochemistry from the same generation of cement or vein, and thus, to determine paleo-fluid flow direction; 2) to show variation trend of reservoir porosity spatially along the flow direction and different microfacies, and temporarily with shoal-up sequence and paleo-fluid geochemistry of different generations; 3) to distinguish dissolution by meteoric water from by deep burial, and determine if present porosity resulted from inhibition on cementation due to petroleum emplacement, or from deep burial dissolution; 4) to address if TSR occurred in gas reservoirs, elucidate the mechanism for deep burial dissolution, explain why porosity varies spatially and temporarily, and finally establish a model to predict reservoir distribution.