發(fā)布時間：2018-07-22 11:40

【摘要】：低滲透致密砂巖天然氣高效勘探和開發(fā)的關(guān)鍵是致密儲層特征及分布規(guī)律的研究評價。川東北元壩地區(qū)須三氣藏儲層的平均孔隙度2.33%,平均滲透率0.082md,屬低滲低孔儲層,而且產(chǎn)能受裂縫發(fā)育程度得影響。本文綜合運用沉積地質(zhì)學、層序地層學、礦物巖石學以及儲層構(gòu)型分析等理論和技術(shù)方法,對川東北元壩地區(qū)須三段沉積相及致密砂巖儲層特征進行了研究,并通過儲層測井響應(yīng)特征對裂縫發(fā)育程度進行了評價,進而對儲層主控因素及分布規(guī)律展開了深入的研究,認為：①須三氣藏為辮狀河三角洲沉積體系,根據(jù)巖心相、測井相、地震相結(jié)合,單井相、連井相分析,結(jié)合砂組劃分,研究縱向沉積演化及砂組橫向沉積微相展布,落實有利微相帶,為分流河道和河口壩。②須三氣藏儲層極為致密,屬低孔低滲儲層。儲層巖石類型以中粗粒鈣屑砂巖、砂礫巖為主；鈣屑砂巖儲集空間以粒間溶孔、膠結(jié)物溶蝕孔、巖屑晶間孔和內(nèi)溶孔為主,其次為粘土礦物晶間孔等；砂礫巖儲集空間以微縫為主。鈣屑砂巖平均孔隙度2.6%,平均滲透率0.0155md；砂礫巖平均孔隙度1.95%,平均滲透率0.0621md。③裂縫具有雙重滲流作用,是儲層是否有效和產(chǎn)能高低的關(guān)鍵控制因素,須三氣藏整體裂縫比較發(fā)育,以構(gòu)造縫為主,與斷層派生縫和層間縫等綜合形成網(wǎng)狀裂縫帶,但各砂組差異比較大,主要分布于1砂組的YL20-YB205井區(qū)、3砂組的YL12-YB6井區(qū)和YL7井區(qū),含氣性較好、含氣砂體厚度大。④須三致密儲層發(fā)育的主控地質(zhì)因素與巖性、有利儲層厚度以及裂縫發(fā)育程度密切相關(guān),儲層段主要巖相為中-粗粒鈣屑砂巖相及砂質(zhì)礫巖相；縱向上儲層巖性變化較大,巖性變粗,孔隙類型及結(jié)構(gòu)變差,局部有利巖性發(fā)育帶和裂縫發(fā)育區(qū),有效儲層較發(fā)育。⑤須三氣藏致密儲層發(fā)育特征變化大,根據(jù)巖性及厚度、物性、儲集空間與裂縫發(fā)育程度劃分有利區(qū)和較有利區(qū),并劃分儲層類型：儲層以Ⅲ類儲層為主,優(yōu)質(zhì)儲層中以Ⅱ類儲層為主,Ⅰ類儲層較少。平面上儲層主要集中在該區(qū)西部,厚度較大、含氣性好,而中部及東部以含氣性弱、厚度��；4個巖性有利主河道評價潛力區(qū)主要為1砂組的YL10-YB205井區(qū)、3砂組的YL12-YB6井區(qū)和YL7井區(qū)。
[Abstract]:The key to high efficiency exploration and development of low permeability tight sandstone natural gas is the study and evaluation of tight reservoir characteristics and distribution law. The average porosity and average permeability of the reservoir are 2.33 and 0.082 mdrespectively, which belong to low permeability and low porosity reservoir, and the productivity is affected by the fracture development degree. Based on the theories and techniques of sedimentary geology, sequence stratigraphy, mineral petrology and reservoir configuration analysis, the sedimentary facies and tight sandstone reservoir characteristics of the third member in Yuanba area, northeast Sichuan are studied in this paper. The degree of fracture development is evaluated by the response characteristics of reservoir logging, and the main controlling factors and distribution law of reservoir are studied deeply. It is considered that the reservoir is a braided river delta sedimentary system, according to the core facies and logging facies, the reservoir is a braided river delta sedimentary system. The combination of seismic facies, single-well facies, multi-well facies analysis, combined with sand formation division, the study of longitudinal sedimentary evolution and the distribution of transverse sedimentary microfacies of sand formation, the implementation of favorable microfacies zone, the reservoir is extremely compact for distributary channel and estuarine dam .2 gas reservoir. It belongs to low porosity and low permeability reservoir. The reservoir rock types are mainly medium coarse calcareous sandstone, sand gravel, intergranular dissolution pore, cemented dissolution pore, lithic intergranular pore and internal dissolved pore, followed by clay mineral intergranular pore, etc. The reservoir space of calcareous sandstone is mainly composed of intergranular dissolution pore, cemented material dissolution pore, lithic intergranular pore and internal dissolved pore, etc. The microfracture is the main reservoir space of sandy gravel. The average porosity of calcareous sandstone is 2.6, the average permeability is 0.0155md, the average porosity of gravel is 1.95, and the average permeability of 0.0621md.3 fracture is double percolation, which is the key controlling factor of reservoir effectiveness and productivity. The network fracture zone is formed mainly by structural fractures, combined with fault derived fractures and interbedded fractures, but the differences among sand groups are quite great. They are mainly distributed in YL20-YB205 well area, YL20-YB205 well area, YL12-YB6 well area and YL7 well area, where the gas content is good, and the gas content of YL12-YB6 well and YL7 well area is better than that of YL20-YB205 well group. The main controlling geological factors for the development of gas-bearing sand body are closely related to lithology, favorable reservoir thickness and fracture development degree. The main lithofacies in the reservoir section are medium-coarse calcareous sandstone facies and sandy conglomerate facies. Longitudinally, reservoir lithology changes greatly, lithology becomes thicker, pore type and structure become worse, local favorable lithologic development zone and fracture development zone, effective reservoir has more development characteristics than that of developing 5. 5 gas reservoir, according to lithology and thickness, it is necessary to change the characteristics of tight reservoir in effective reservoir, according to lithology and thickness. Physical properties, reservoir space and fracture development degree are divided into favorable areas and favorable areas, and the types of reservoirs are classified as follows: type 鈪，

本文編號：2137335