CAJ | 학술논문

通过对桑植—石门复向斜及相邻地区震旦系—三叠系方解石脉和围岩的碳氧同位素、锶同位素对比，结合方解石脉中流体包裹体测试分析，研究了桑植—石门地区古流体特征及其油气保存意义。下古生界围岩87 Sr／86 Sr部分高于同期海水，也高于方解石脉，表明围岩在裂隙形成之前受到高87 Sr／86 Sr流体改造。桑植—石门复向斜北翼温泉附近的方解石脉体具高87 Sr／86 Sr、低δ13 C、低δ18 O特征，显示大气水参与了方解石脉沉淀，逆断层可能在形成之初就不具封闭性。流体包裹体盐度和均一温度指示，桑植—石门地区上寒武统娄山关组上覆盖层残余厚度小于3 km，不具封闭能力；中寒武统孔王溪组方解石脉流体包裹体高盐度表明膏盐盖层在研究区广泛分布，在埋深超过2 km条件下对下伏地层具有较好的封盖能力。桑植—石门复向斜田二垭、向家垭、车坊背斜圈闭、桥头、中坪隐伏圈闭保存条件较好，除田二垭背斜外，可以同时将震旦系灯影组、寒武系清虚洞组白云岩作为勘探目的层。
통과대상식—석문복향사급상린지구진단계—삼첩계방해석맥화위암적탄양동위소、송동위소대비，결합방해석맥중류체포과체측시분석，연구료상식—석문지구고류체특정급기유기보존의의。하고생계위암87 Sr／86 Sr부분고우동기해수，야고우방해석맥，표명위암재렬극형성지전수도고87 Sr／86 Sr류체개조。상식—석문복향사북익온천부근적방해석맥체구고87 Sr／86 Sr、저δ13 C、저δ18 O특정，현시대기수삼여료방해석맥침정，역단층가능재형성지초취불구봉폐성。류체포과체염도화균일온도지시，상식—석문지구상한무통루산관조상복개층잔여후도소우3 km，불구봉폐능력；중한무통공왕계조방해석맥류체포과체고염도표명고염개층재연구구엄범분포，재매심초과2 km조건하대하복지층구유교호적봉개능력。상식—석문복향사전이오、향가오、차방배사권폐、교두、중평은복권폐보존조건교호，제전이오배사외，가이동시장진단계등영조、한무계청허동조백운암작위감탐목적층。
The paleo?fluid characteristics and hydrocarbon preservation in the Sangzhi-Shimen synclinorium and adjacent areas are discussed using comparisons of C, O, and Sr isotopes between the calcite veins and surrounding rocks in the Sinian and Triassic formations and combined with the tests of fluid inclusions in calcite veins. The 87Sr/ 86Sr values of surrounding rocks in the Lower Paleozoic are higher than those of contemporary seawater and calcite veins, which suggests that the surrounding rocks had been reformed by fluid with high 87 Sr/ 86 Sr values before fracturing. The calcite veins close to thermal springs in the north of Sangzhi-Shimen synclinorium have high 87 Sr/ 86 Sr values, low δ13 C and low δ18 O values, which can be explained by the mixing of meteoric water during calcite vein deposition and suggests that reverse faults might have been open when they were formed. The salinity and homogenization temperature of fluid inclusions shows that the residual cap formations above the Upper Cambrian Loushanguan Formation are less than 3 km thick with poor sealing capacity. The high salinity of calcite inclusions in the Middle Cambrian Kongwangxi Formation showed that gypsum salt cap layers are distributed widely in the study area, and the gypsum salt layers buried over 2 km deep have excellent sealing capacity. The preservation conditions of the Tianerya, Xiangjiaya, Chefang anticline traps, and the Qiaotou, Zhongping buried structural traps are favorable. The dolomites in the Sinian Dengying Formation and Cambrian Qingxudong Formation are exploration targets except for those in the Tianerya anticline.