龙门山北段地下水动力特征及油气保存条件研究-矿产普查与勘探专业论文.docx

因水逐渐取代岩石孔隙中的流体（包括水和油气）,进而破坏河湾场背斜圈闭内的油气藏。（3）中坝地区西北部，龙门山山前发育走向北东-南西，倾向北西的阻水断 层；中坝西南部，发育有走向北东-南西，倾向北西的彰明断层，同样具有封闭 性。龙门山山前断层能有效阻隔断层上盘地表水向下盘及盆地内侵入。区内三叠 系储集层深埋地腹，不能接受大气降水的渗入，与渗入成因水失去水力联系，因 此该地区沉积成因水水动力系统与渗入成因水水动力系统相互独立，互不相干， 油气藏不会遭受渗入成因承压水水动力的破坏，因而油气保存条件较好，形成了 有效圈闭。再者，位于气田西南部的彰明断层具有封闭性，这为油气在背斜圈闭 内聚集成藏提供了重要条件。（4）中坝气田水呈现出高矿化度，CaCl2 和 Na2SO4 水型为基本特征，属于 封闭的沉积成因水。封闭、地下水交替停滞的还原环境有利于油气的保存，油气 得以聚集成藏。勘探远景区应在远离山前带的地区，勘探层位应以三叠统及上二叠统碳酸盐 岩深盆气为主。关键词：龙门山北段遥感地质解译水动力油气保存条件AbstractCharacteristics of Groundwater In the North segment of Longmenshan and it’s Hydrocarbon Preservation ConditionsIntroduction of the author: Cheng Jian, male, was born in August, 1984 whose tutor was Professor Wang-Duoyi .He graduated from Chengdu University of Technology in Mineral Resource Prospecting and Exploration major and was granted the Master Degree in June, 2010.AbstractLongmenshan divided by three major NE-trending faults, i. e, from west to east the Maoxian-Wenchuan fault, Beichuan-Yinxiu fault, Anxian-Guanxian fault into “back-mountain belt”, “front-mountain belt” and “piedmont belt”. They are Songpan-Ganzi fold-belt, Maoxian-Wenchuan ductile shear belt, Longmenshan over- thrust nappy belt and foreland basin of western Sichuan. On the vertical direction of structural-line, Longmenshan divided by HanWang, DuJiangyan (Guanxian), TianQuan.YaAn into “North section”, “Middle section” and “South section” from north to south. Longmenshan thrust belt has four major slip horizons on the longitudinal of it:①coal measure stratum of XuJiahe formation; ②anhydrock and salt beds of UpperLeiKoupo; ③mud rock and muddy limestone of FeiXianguan formation and Lower Permian; ④mud rock and muddy limestone of Cambrian and Lower Devonian. Northsection of Longmenshan has a good condition of hydrocarbon source rocks, rocks-reservoir-cap combinations and traps. A lot of oil and gas seepages have been discovered wildly. The hydrocarbon seepage distributed in the sedimentary rocks from Silurian (Paleozoic) to Jurassic (Mesozoic).T