CAJ | 학술논문

柴达木盆地西部南区新生界主要为咸化湖盆沉积，咸化环境提高了其烃类转化率，但其对储层的控制作用尚待进一步明确。通过高温高压试验模拟了地层条件下成岩流体与岩石矿物之间的物理化学作用，进而研究咸化环境中有机质演化过程中产生的有机酸对储层的改造作用。结果表明：酸性流体对岩石矿物的溶蚀作用增加了其孔隙度，但渗透率的变化存在差异性；当岩石中含有石膏和铁白云石时，铁白云石在石膏的催化作用下极易发生溶蚀作用，反应生成的 Fe2＋、Mg2＋促进了高岭石向针叶状绿泥石的转化，从而堵塞孔隙喉道，造成岩石渗透率的下降；岩石中石膏的发育是造成高温高压地层中方解石发生沉淀的主要原因，相同条件下石膏比方解石更易溶解，其产生的过饱和钙造成方解石的沉淀，但岩石的孔隙度有所增大，因为方解石的沉淀作用造成的储集空间减小量小于石膏和长石等易溶矿物溶解造成的储集空间增大量。
시체목분지서부남구신생계주요위함화호분침적，함화배경제고료기경류전화솔，단기대저층적공제작용상대진일보명학。통과고온고압시험모의료지층조건하성암류체여암석광물지간적물이화학작용，진이연구함화배경중유궤질연화과정중산생적유궤산대저층적개조작용。결과표명：산성류체대암석광물적용식작용증가료기공극도，단삼투솔적변화존재차이성；당암석중함유석고화철백운석시，철백운석재석고적최화작용하겁역발생용식작용，반응생성적 Fe2＋、Mg2＋촉진료고령석향침협상록니석적전화，종이도새공극후도，조성암석삼투솔적하강；암석중석고적발육시조성고온고압지층중방해석발생침정적주요원인，상동조건하석고비방해석경역용해，기산생적과포화개조성방해석적침정，단암석적공극도유소증대，인위방해석적침정작용조성적저집공간감소량소우석고화장석등역용광물용해조성적저집공간증대량。
The sedimentary environment in the south area of western Qaidam Basin is mainly saline lacustrine basin in Cenozoic. Saline environment improves the conversion rate of hydrocarbon,but the control on reservoir is not clear.Based on the high-temperature and high-pressure test,the physical-chemical reaction between diagenetic fluid and mineral in geological condition was simulated, and the reconstruction of organic acid produced in the process of evolution of organic matter on reservoir in saline environment was discussed.The results show that the dissolution of acid fluid on mineral increases the porosity,but the change of permeability is different;when the rocks contain plaster and ankerite,the ankerite dissolves easily under the catalysis of plaster,and Fe2+ and Mg2+ formed by the chemical reaction improve the conversion of kaolinite to needle-shaped chlorite, and consequently pore throat blocked decreases the permeability;the precipitation of calcite in high-temperature and high-pressure stratum is caused by the development of plaster in rock,and the plaster dissolves more easier than the calcite under the same condition;the supersaturated Ca causes the precipitation of calcite,and the porosity of rock increases because the reservoir space reduced by precipitation of calcite is less than that released by the dissolution of deliquescent minerals such as plaster and feldspar.