元坝地区中侏罗统千佛崖组储层特征

发布时间：2019-01-20 09:16

【摘要】：低孔低渗(特低孔特低渗)油气藏在我国油气资源中占有十分重要的地位,但目前勘探和开发技术上尚不完善。川东北元坝地区就是典型的低孔低渗透气藏,现阶段对于它的具体地质特征仍不是十分清楚。近年来,四川东北元坝地区千佛崖组勘探取得了重大的进展,表现出了良好的勘探前景。但是因为砂岩储层近物源,埋藏深,后期又经历了广泛而复杂的成岩作用,变得十分致密,对优质储层的预测造成了困难。因此,本文以沉积学、储层地质学、测井地质学、矿物岩石学、地球化学以及储层综合评价等理论方法为指导,使用各种现代等测试手段,结合物性资料等,重点研究储层和成岩作用等特征,并最终论述了影响储层物性的各种因素,在此基础上建立了储层形成与演化模式。本区千佛崖组储层岩石类型包括岩屑石英砂岩、长石岩屑砂岩、碳酸盐岩屑砂岩、硅岩屑砂岩以及砂砾岩五种岩石类型。其中,岩屑石英砂岩成分成熟度中等偏低或中等偏高,结构成熟度高或中等偏高;长石岩屑砂岩成分成熟度低,结构成熟度中等;碳酸盐岩屑砂岩成分成熟度低,结构成熟度中等偏高;硅岩屑砂岩成分成熟度低,结构成熟度低。碎屑组分以富岩屑、贫长石为特征,填隙物以碳酸盐、硅质和粘土矿物为主,岩屑以硅质岩岩屑、碳酸盐岩屑及变砂岩岩屑为主。本区千佛崖组储层主要分布千二段、千三段。储层总体以低孔低渗储层为主。孔隙度分布范围为1.07%~17.02%,平均4.017%,主要分布区间为2%~5%。渗透率分布范围为0.001×10-3~1.51×10-3μm2,平均0.159×10-3μm2,主要分布区间为0.001×10-3~0.01×10-3μm2。储层主要类型为孔隙-裂缝型,储集空间类型按成因可分为剩余原生粒间孔、次生孔隙和洞、裂缝。次生孔隙可分为粒间溶孔、粒间微孔、粒内溶孔、粒内微孔、铸模孔及超大溶孔。本区储层储集类型以剩余原生粒间孔、粒间溶孔、粒间微孔、粒内溶孔、裂缝为主要的储集空间,多为小~微孔,面孔率低。元坝地区千佛崖组主要发育陆相三角洲前缘水下分流河道微相和浅湖-半深湖亚相,局部发育滨湖亚相,特别是在典型湖相区出现的砂岩明显增厚的三角洲前缘沉积,更有利于油气储集。建立了三角洲平原-三角洲前缘-前三角洲-滨湖-浅湖-半深湖沉积演化模式。该区千佛崖组储层成岩作用复杂。成岩作用对砂岩储集性能具有深刻的影响。压实作用是该区储层孔隙破坏的主要因素,颗粒呈线到凹凸接触;胶结作用进一步加强了储层的致密性,胶结物以硅质、碳酸盐和粘土矿物为主;溶解作用对储层具有重要影响,较大程度提高了孔隙度和渗透率。研究区砂岩储层已达到中成岩阶段B期。储层物性受成岩、沉积和构造的多重因素共同控制。本论文系统总结了储层物性的两个重要控制因素,即沉积作用、成岩作用。沉积作用对储层的影响实质是对储层岩石类型和结构组分特征的影响,沉积体系决定了后期岩石的成岩作用类型和强度;成岩作用不仅影响储层储集空间的演化和孔喉结构特征,并最终决定了储层物性的好坏和现今储层的分布状况。通过前人的研究成果及大量测试分析数据得出本区成岩阶段演化程度较高,总体处于中成岩B期,早成岩晚期和中成岩早期的溶蚀作用、中成岩晚期的破裂作用是储层储集性改善的重要作用。
[Abstract]:The low-porosity and low-permeability (low-permeability) oil-gas reservoir plays an important role in the oil and gas resources in China, but it is still not perfect at present. The northeast of Sichuan is the typical low-porosity and low-permeability gas reservoir, and it is still not clear at the present stage for its specific geological characteristics. In recent years, the exploration of the Qianfo Cliff Group in the northeast of Sichuan has made great progress, showing a good prospect of exploration. However, because of the near-material source, the burial depth and the late stage of the sandstone reservoir, it has undergone extensive and complicated diagenesis, so it becomes very dense, and it is difficult to predict the high-quality reservoir. Therefore, by using the methods of sedimentology, reservoir geology, logging geology, mineral petrology, geochemistry and comprehensive reservoir evaluation, this paper mainly studies the characteristics of reservoir and diagenesis by using various modern and other test methods, combining physical property data and so on. Finally, various factors that affect the physical property of the reservoir are discussed, and the formation and evolution model of the reservoir is established. The rock types of the Qianfo Cliff Formation in this area include five types of rock types, such as the rock debris quartz sandstone, the feldspar debris sandstone, the carbonate rock sandstone, the silicon rock debris sandstone and the glutenite. Among them, the maturity of the rock is low or the medium is high, the maturity of the structure is high or the middle is high, the maturity of the rock is low, the maturity of the structure is middle, the maturity of the carbonate rock sandstone is low, and the maturity of the structure is high; The composition of the silicon-cuttings sandstone is low in maturity and low in structure. The debris component is characterized by rich rock and feldspar, and the interstitial material is mainly composed of carbonate, siliceous and clay minerals, and the rock cuttings are mainly rock, rock, carbonate and sandstone. The reservoir of the Qianfo Cliff Formation in this area is mainly distributed in a thousand-second section and a thousand-third section. The reservoir is mainly low-porosity and low-permeability reservoir. The distribution of porosity is 1. 07% ~ 17. 02%, with an average of 4,017%, and the main distribution area is 2% ~ 5%. The distribution range of permeability is 0. 001-10-3-1.51-10-3. m u.m2, with an average of 0.159-10-3. m u.m2, and the main distribution area is 0. 001-10-3-0. 01-10-3. m The main types of the reservoir are the pore-fracture type, and the type of the reservoir space can be divided into the remaining primary and secondary pores, secondary pores and holes and cracks. The secondary pores can be divided into the inter-particle dissolving hole, the inter-particle micro-hole, the inner-particle dissolving hole, the intragranular micro-hole, the mold hole and the super-large dissolving hole. The reservoir types in this area are the remaining primary inter-grain pore, the inter-particle dissolution pore, the inter-particle micro-pores, the intragranular soluble pores, the fracture is the main reservoir space, the number is small to micro-pores, and the surface rate is low. The subfacies of the subfacies and the shallow lake-semi-deep lake subfacies of the subfacies of the continental delta and the subfacies of the shallow lake-semi-deep lake and the local development of the subfacies of the Binhu subfacies, in particular in the typical lake facies area, are more beneficial to the reservoir of oil and gas. The sedimentary evolution model of the delta plain-delta front-front-delta-Binhu-shallow lake-semi-deep lake was established. The reservoir diagenesis of the Qianfo Cliff Formation in this area is complicated. The diagenesis has a profound effect on the reservoir performance of the sandstone. The compaction effect is the main factor of the reservoir pore destruction, and the particles are in line to the concave and convex contact; the cementation effect further enhances the compactness of the reservoir, and the cement is mainly the siliceous, carbonate and clay minerals; the dissolution effect has an important influence on the reservoir, and the porosity and the permeability are improved to a greater extent. The sandstone reservoir in the study area has reached the middle diagenetic stage B. The physical properties of the reservoir are controlled by the multiple factors of diagenesis, deposition and construction. In this paper, two important control factors of reservoir physical property are summarized, that is, the diagenesis and diagenesis. The effect of the diagenesis on the reservoir is the influence of the reservoir rock type and the structural component, the sedimentary system determines the type and the strength of the diagenesis of the late rocks, and the diagenesis not only affects the evolution of the reservoir space and the structural characteristics of the pore, and finally determines the reservoir physical property and the distribution condition of the present reservoir. The late diagenetic stage of diagenetic stage, the early diagenetic stage and the early diagenetic stage of the diagenetic stage, the rupture of the late diagenetic stage is an important function of reservoir improvement.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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