本文選題：筇竹寺組 + 頁巖氣　； 參考：《中國礦業(yè)大學(xué)》2015年碩士論文

【摘要】：下寒武統(tǒng)筇竹寺組是我國頁巖氣勘探開發(fā)的有利層系之一,其形成時間早、熱演化程度高,經(jīng)歷了復(fù)雜的地質(zhì)演化歷程。從成藏角度認(rèn)識筇竹寺組頁巖氣地質(zhì)特征,很有必要。論文以滇東曲靖地區(qū)下寒武統(tǒng)筇竹寺組為研究對象,通過資料收集整理、野外地質(zhì)調(diào)查、巖芯觀測、實驗測試分析等手段,從地質(zhì)背景、沉積環(huán)境、源巖-儲層特征、成藏地質(zhì)過程、賦存特征與保存條件五個方面對曲靖地區(qū)筇竹寺組頁巖氣成藏地質(zhì)特征進行了分析。研究區(qū)位于上揚子板塊南緣滇黔隆褶帶,在區(qū)域地質(zhì)背景研究基礎(chǔ)上,結(jié)合野外地質(zhì)調(diào)查成果,系統(tǒng)梳理了本區(qū)沉積-構(gòu)造演化特征,將其劃分為四個階段:原古特提斯洋階段、古特提斯洋階段、燕山運動階段、喜馬拉雅運動階段。利用層序地層學(xué)理論,將區(qū)內(nèi)下寒武統(tǒng)劃分為6個三級層序,形成一個有序的海水進退旋回,其中筇竹寺組位于Sq2與Sq3層序。將筇竹寺組劃分為淺水陸棚、半深水陸棚和深水陸棚三個沉積亞相及六個沉積微相,其沉積環(huán)境經(jīng)歷了四個主要的演化過程。筇竹寺組富有機質(zhì)泥頁巖主要發(fā)育于Sq2層序海侵體系域,富有機質(zhì)泥頁巖厚度70~120m,埋深0~4500m。筇竹寺組富有機質(zhì)泥頁巖有機質(zhì)類型以I型為主,有機質(zhì)成熟度(Ro)4.2%,有機質(zhì)豐度(TOC)平均2.88%。筇竹寺組頁巖儲層以炭質(zhì)頁巖、粉砂質(zhì)頁巖為主,石英含量較高,孔隙主要有機質(zhì)孔、粒內(nèi)孔、粒間孔等類型。根據(jù)壓汞曲線形態(tài),區(qū)內(nèi)頁巖儲層可分為兩種類型,以第二類儲層為主,其壓汞曲線滯后環(huán)較窄,連通性較差,孔徑分布不連續(xù),孔隙度偏低,平均為2.53%。與龍馬溪組相比,本區(qū)筇竹寺組頁巖熱演化程度更高,儲層孔隙度偏低、孔隙連通性偏差。上述特征可能指示了過高的熱演化程度不利于頁巖儲層孔隙的發(fā)育。運用“構(gòu)造-埋藏-受熱-生烴”的研究思路,探討了本區(qū)頁巖氣成藏的地質(zhì)過程。地層厚度趨勢分析法、沉積速率法研究表明,QD1井印支期以來累計剝蝕量超過5800m。筇竹寺最大埋深出現(xiàn)在中三疊世晚期,埋深達(dá)7000m,最大受熱溫度可達(dá)270℃左右,主要生烴時期為C-P時期。總結(jié)了本區(qū)筇竹寺組頁巖氣藏的三個主要特點:沉積環(huán)境有利于形成良好的物質(zhì)基礎(chǔ),儲層成巖改造作用強烈,成藏過程生烴期早、隆升強烈。等溫吸附實驗揭示筇竹寺組最大吸附量平均2.95cm3/g,氣測錄井揭示筇竹寺組全烴含量平均0.011%,現(xiàn)場解析實驗表明其平均含氣量約0.54m3/t。從構(gòu)造條件、地下水條件、蓋層特征、氣體組分四個方面分析了本區(qū)筇竹寺組頁巖氣保存條件。總體而言,本區(qū)筇竹寺組頁巖氣藏淺部保存條件較差,推測深部有較好保存條件。
[Abstract]:The Qiongzhusi formation of the Lower Cambrian is one of the favorable strata for shale gas exploration and development in China. It is necessary to understand the geological characteristics of shale gas in Qiongzhusi formation from the perspective of reservoir formation. This paper takes Qiongzhusi formation of Lower Cambrian in Qujing area of eastern Yunnan as the research object. By means of data collection, field geological investigation, core observation, experimental test and analysis, the paper analyzes the geological background, sedimentary environment, source rock-reservoir characteristics, and so on. The geological characteristics of shale gas accumulation of Qiongzhusi formation in Qujing area were analyzed from five aspects: the geological process of reservoir formation, the characteristics of occurrence and the conditions of preservation. The study area is located in the Yunnan-Qianlong fold belt of the southern margin of the upper Yangtze plate. On the basis of the study of the regional geological background and combined with the results of the field geological survey, the sedimentary and tectonic evolution characteristics of the area are systematically combed. It can be divided into four stages: the PaleoTethys stage, the Yanshanian stage and the Himalayan stage. Based on sequence stratigraphy, the Lower Cambrian in this area is divided into six third-order sequences to form an orderly seawater advance and retreat cycle, in which Qiongzhusi formation is located in the Sq2 and Sq3 sequences. Qiongzhusi formation is divided into three sedimentary subfacies: shallow water shelf, semi-deep water shelf and deep water shelf, and six sedimentary microfacies. The sedimentary environment of Qiongzhusi formation has undergone four main evolution processes. The organic-rich shale of Qiongzhusi formation is mainly developed in the Sq2 sequence transgressive system tract, with a thickness of 70 ~ 120m and a depth of 0 ~ 4500m. In Qiongzhusi formation, the organic matter types of organic matter rich shale are mainly type I, organic matter maturity (Ro) 4.2 and organic matter abundance (TOC) 2.88 on average. The shale reservoirs of Qiongzhusi formation are mainly carbonaceous shale, silty shale, high quartz content, main organic pore, intragranular pore, intergranular pore and so on. According to the shape of mercury injection curve, shale reservoir in this area can be divided into two types, mainly the second type reservoir. The hysteresis loop of mercury injection curve is narrower, the connectivity is poor, the pore size distribution is discontinuous, the porosity is low, the average is 2.53. Compared with Longmaxi formation, Qiongzhusi formation in this area has higher thermal evolution degree, lower porosity and deviation of pore connectivity. These characteristics may indicate that too high thermal evolution is not conducive to the development of shale reservoir pores. The geological process of shale gas accumulation in this area is discussed by using the research idea of "tectonic-buried, thermal-hydrocarbon-generating". The analysis of formation thickness trend and sedimentation rate method show that the cumulative denudation amount of QD1 well is more than 5800m since the Indosinian period. The maximum buried depth of Qiongzhusi appeared in the late Middle Triassic, with a buried depth of 7 000 m and a maximum heating temperature of about 270 鈩，

本文編號：2108796