川西坳陷上侏罗统蓬莱镇组水-岩相互作用研究

根据川西坳陷上侏罗统中段蓬莱镇组储层的成岩作用具有长石溶解,硅质和方解石胶结的特点,应用GWB软件分析各井矿物的溶解和沉淀,得到平面等值线图,并对蓬莱镇组有利储集相带进行了预测.研究结果表明:计算得到的长石、方解石含量等值线图与实际测量得到的长石、方解石含量等值线图的变化规律一致,说明所选的模拟条件可信;影响本区矿物溶解与沉淀的主要因素是长石含量、地温和pH值;孝泉和新场地区地温低、长石含量中等、pH值低,为次生孔隙发育的Ⅰ类区;马井、新都和洛带地区地温梯度、长石含量及pH值不完全匹配,为次生孔隙发育的Ⅱ类区;温江地区为Ⅲ类区.

Water-rock interaction of Penglaizhen formation of upper Jurassic in the west of Sichuan depression

Reservoir diagenesis of Penglaizhen formation of upper Jurassic in the western Sichuan depression is characterized by feldspar dissolution, siliceous and calcite cementation. According to the characteristics, the amount of mineral dissolution and cementation for each well was calculated with the software GWB, then the isoline map was made, and the result was contrasted with the one gained with the actual measurement. The result of simulation is consistent with the actual measurement, which indicates that the simulation condition adopted is creditable. Then another simulation was carried out to investigate the factors which control the physical properties of reservoir, such as the feldspar content, the geothermal gradient and pH value. The growth of Penglaizhen formation reservoir is predicted as follows. Xiaoquan and Xinchang area belong to the primary area of the secondary pore formation with the characteristics of low geothermal gradient, middle feldspar content and low pH value; Majing, Xindu and Luodai belong to the subordinate area due to the mismatch of the geothermal gradient, feldspar content and pH value; Wenjiang belongs to the worst area.