石油实验地质
石油實驗地質
석유실험지질
Petroleum Geology and Experiment
2015年
5期
561-565,574
,共6页
气藏特征%气藏保存%输导体系%侏罗系%川西坳陷%四川盆地
氣藏特徵%氣藏保存%輸導體繫%侏囉繫%川西坳陷%四川盆地
기장특정%기장보존%수도체계%주라계%천서요함%사천분지
gas reservoir characteristics%gas preservation%migration system%Jurassic%Western Sichuan Depression%Sichuan Basin
川西坳陷中段侏罗系发育大面积低丰度岩性、构造—岩性气藏。气藏普遍具有多层叠置、局部富集高产、无明显气水边界、低温、超压的特征。结合各构造单元侏罗系具体成藏条件研究认为,侏罗系整体为“下生上储”式成藏组合,天然气主要来源于下伏须家河组四、五段烃源岩。因此,具备良好的沟通源、储层垂向运移输导体系是天然气富集成藏的关键因素。侏罗系各组段砂岩储层物性纵、横向变化较大,受渗透率级差影响,相对优质储层的发育程度是天然气藏高产富集的主要控制因素。龙门山前及龙泉山两侧发育大量直通地表的断裂,不仅直接破坏了断裂带附近的盖层条件,同时破坏了与之相接的斜坡区侏罗系砂体上倾方向的封闭性,有效的圈闭是侏罗系富集高产的重要因素。
川西坳陷中段侏囉繫髮育大麵積低豐度巖性、構造—巖性氣藏。氣藏普遍具有多層疊置、跼部富集高產、無明顯氣水邊界、低溫、超壓的特徵。結閤各構造單元侏囉繫具體成藏條件研究認為,侏囉繫整體為“下生上儲”式成藏組閤,天然氣主要來源于下伏鬚傢河組四、五段烴源巖。因此,具備良好的溝通源、儲層垂嚮運移輸導體繫是天然氣富集成藏的關鍵因素。侏囉繫各組段砂巖儲層物性縱、橫嚮變化較大,受滲透率級差影響,相對優質儲層的髮育程度是天然氣藏高產富集的主要控製因素。龍門山前及龍泉山兩側髮育大量直通地錶的斷裂,不僅直接破壞瞭斷裂帶附近的蓋層條件,同時破壞瞭與之相接的斜坡區侏囉繫砂體上傾方嚮的封閉性,有效的圈閉是侏囉繫富集高產的重要因素。
천서요함중단주라계발육대면적저봉도암성、구조—암성기장。기장보편구유다층첩치、국부부집고산、무명현기수변계、저온、초압적특정。결합각구조단원주라계구체성장조건연구인위,주라계정체위“하생상저”식성장조합,천연기주요래원우하복수가하조사、오단경원암。인차,구비량호적구통원、저층수향운이수도체계시천연기부집성장적관건인소。주라계각조단사암저층물성종、횡향변화교대,수삼투솔급차영향,상대우질저층적발육정도시천연기장고산부집적주요공제인소。룡문산전급룡천산량측발육대량직통지표적단렬,불부직접파배료단렬대부근적개층조건,동시파배료여지상접적사파구주라계사체상경방향적봉폐성,유효적권폐시주라계부집고산적중요인소。
In the middle section of the Western Sichuan Depression, lithologic and tectonic?lithologic gas reser?voirs are widespread in the Jurassic. These reservoirs feature multiple layers, local enrichment, no obvious gas/water boundary, low temperature and overpressure. Accumulation conditions in the Jurassic indicate that gases were mainly sourced from the Lower Jurassic and preserved in the Upper Jurassic. The fourth and fifth members of the Xujiahe Formation provided important source rocks for natural gases. Vertical pathways connections between source rocks and reservoirs were the factors controlling natural gas accumulations. The physical properties of the Jurassic sandstones varied both horizontally and vertically. The development of favorable reservoirs also influenced the enrichment of natural gases. A large amount of vertical fractures which extended directly to the earth surface were found in the front of the Longmen Mountain and on both sides of the Longquan Mountain. They destroyed the neighboring cap formations, and damaged the sealing capacity of the Jurassic sand bodies in the adjacent slope area. Effective traps were necessary for natural gas enrichment in Jurassic.