摘要
为了扩大四川盆地中三叠统雷口坡组天然气勘探的范围,以川西南部莲花山地区雷口坡组三段(以下简称雷三段)为研究对象,在前人研究的基础上,通过野外露头观测、岩心描述和薄片鉴定,结合地球物理资料,从沉积相、储层特征及源储匹配关系等方面进行了分析,并评价了天然气勘探潜力。研究结果表明:①雷口坡组沉积期受周围古陆交替崛起和海底隆起的影响,川西南处于封闭—半封闭状态,水体能量有限,其中雷三段水体能量较高,颗粒滩发育,岩性为砂屑、藻屑白云岩,储集空间主要为溶蚀孔和晶间溶孔,储集性能优越,局部发育的微裂缝为天然气的运聚提供了良好的渗流通道;②构造控制面积大,提供了良好的油气聚集场所,发育的断层有利于下盘上三叠统须家河组一段生成的天然气侧向运移至上盘雷三段中聚集成藏;③上覆雷四段发育的膏岩为天然气在雷三段聚集成藏提供了良好的盖层条件。结论认为,莲花山地区雷三段储层厚度大、源储匹配关系好、天然气成藏条件优越、可控资源丰富,为川西南部雷口坡组有利的天然气勘探开发区域。
Based on previous results, combined with geophysical data, this study analyzed Leikoupo 3 Member, Lianhuashan area, southwestern Sichuan Basin, from aspects of sedimentary facies, reservoir characteristics, and source-reservoir assem bly by means of field outcrop observation, core description, and thin-section analysis in order to strengthen an exploration prospective of Leikoupo Formation. Results show that (1) during the sedimentation of Leikoupo Formation influenced by not only alternative and sharp rise of surrounding paleo-continent but also submarine uplift, the southwestern Sichuan Basin was in the closed and semi-closed state and the water energy was limited. Leikou 3 Member is characterized by higher water energy and developed grain beach, and composed of arenite and algal dolomites. Its reservoir space is dominated by dissolved pore and intercrystalline dissolved pore, and its property is good. Locally developed microfactures may provide better pathway for gas migration and accumulation;(2) there is a large area controlled by structure conducive for hydrocar bon accumulation. Developed faults are favorable for gas generated in the footwall Xujiahe 1 Member then lateral migrating to the hanging-wall Leikoupo 3 Member to accumulate there;and (3) gypsums in the overlying Leikoupo 4 Member may provide good caprock conditions for gas accumulating in Leikoupo 3 Member. In conclusion, owing to large thickness, good source-reservoir assembly, advantageous reservoir-forming conditions, and abundant controllable resources, Leikoupo 3 reservoirs in Lianhuashan area should be a favorable belt for exploration and development of Leikoupo Formation in southwestern Sichuan Basin.
作者
刘柏
王旭丽
辛荣跃
樊仕海
孙志昀
田云英
唐明
Liu Bai;Wang Xuli;Xin Rongyue;Fan Shihai;Sun Zhiyun;Tian Yunying;Tang Ming(Northwestern Sichuan Gas District,PetroChina Southwest Oil&Gasfield Company,Jiangyou,Sichuan 621709,China)
出处
《天然气技术与经济》
2020年第1期27-31,52,共6页
Natural Gas Technology and Economy
关键词
四川盆地西南部
莲花山地区
中三叠统
雷口坡组三段
储层特征
勘探潜力
Southwestren Sichuan Basin
Lianhuashan area
Middle Triassic series
Leikoupo 3 Member
Reservoir charac teristics
Exploration Potential
