【作者】 张宗林；

【导师】 孙卫；

【作者基本信息】 西北大学 ， 矿产普查与勘探， 2009， 博士

【摘要】 近年来,随着靖边气田开发程度的不断深入,气田产能建设也逐渐向靖边气田周边进行扩展。经过大量的资料收集、整理、分析和研究工作,对靖边气田北部马五4¹储层特征开展了精细的研究工作,明确了沉积相、成岩作用和古岩溶地貌是储层发育的三个控制因素,研究区碳酸盐岩储层的形成和发育过程极具复杂性,在对储集体的时空展布规律进行深化认识和储层综合评价的基础上,得到如下结论和认识。1.沉积环境是形成有利储层岩石类型的先决条件。研究区沉积环境分析、薄片分析和优势相法编图表明,沉积环境的演变造成马五4¹小层的岩性出现a、b两段之别。马五4^1b段沉积期为海侵期,主体沉积环境为潮间云坪。马五4^1a段沉积期为海退期,发育大量潮上膏云坪和含膏云坪,这是储层发育的有利沉积相带。2.成岩作用是形成有利储集空间的重要保证。研究区马五4¹储层的成岩作用特征为:表生期的岩溶作用和溶蚀作用最利于储层的发育,准同生白云岩化作用未形成有利孔隙,但促进了溶蚀作用的进行;压实、压溶、重结晶作用均不利于储层的发育。3.构造演变是成岩作用进行的有利因素。研究区西北部曾遭受大面积、高强度的风化剥蚀,马五4¹小层上覆奥陶系缺失严重,这有利于岩溶水垂向下渗,并在垂向淋滤溶蚀加深的同时,侧向溶蚀则进一步扩大。溶蚀孔洞、溶蚀裂缝和晶间孔是马五4^1a最主要的储集空间类型。因构造和沉积环境的多变性,单一充填物充填溶蚀孔洞的情况很少,大部分溶蚀孔洞中由多种充填物复合充填,其充填结构较为复杂,但充填程度一般,充填物中富含晶间孔和晶间溶孔。4.孔隙结构的复杂性是储层非均质性的微观体现。岩心物性测试表明,马五4^1a储层孔隙度和渗透率之间的指数函数相关性最强。当孔隙度大于临界孔隙度（约为8%）后,随孔隙度的增大,渗透率的增加趋势非常突出。这表明溶蚀孔洞的发育程度是渗透率提高的基础,而沟通溶蚀孔洞的裂缝及溶蚀裂缝的发育程度是渗透率提高的关键。根据高压压汞试验,并结合岩心和铸体薄片观察,将研究区储层孔隙结构类型分为5种,其中马五4^1a段主要为裂缝—孔洞—孔隙型（占样品的37%）,次为裂缝—孔洞型（占样品的21%）。马五4^1b段主要以微缝—微孔型和微孔型,次为裂缝—孔隙型。5.储层分类评价是开发目标区优选的前提。在多种物性参数等值线图叠加的基础上,再结合沉积相分布和孔隙结构类型,将研究区马五4^1a段储层划分出Ⅰ类、Ⅱ类和Ⅲ类有利区,其中,Ⅰ类、Ⅱ类有利区储渗性能好。储层分类评价结果与单井动态无阻流量吻合较好。Ⅰ+Ⅱ类有利区面积之和为有利区总面积的40%,但其储量占到总储量的60%,Ⅰ+Ⅱ类有利区是靖边气田北部最有前景的勘探和开发目标区。对气田北部和东部的马五4¹小层储渗性能进行了对比分析,气田北部的开发前景更好。更多还原

【Abstract】 With the aggravation of the exploitation degree,the productivity construction projects of Jingbian gas field has expended to the peripheral area in recent years.This paper has made a refined research of the characteristics of Ma5-4-1 reservoir depends,on the collection and treatment work of the data as well as the deep analysis.Based on the thorough understanding of the reservoir bodies’temporal-spacial distribution regularities,the comprehensive evaluation of the reservoir,together with the clear understanding about that the formation and development process of the carbonate reservoir in the study area is very complex with sedimentary facies,diagenesis and peleokarst geomorphology as the three main controlling factors,conclusions come as follows:1.Sedimentary environment is the precondition of favorable rock types for the reservoir. Analysis of the sedimentary environment,the slice analysis and the map complation of the advantage facies shows that the evolution of sedmentary environment has made the differences between the a member and the b member of Ma5-4-1 reservoir.It was transgression stage when a member developed,which has made intertidal dolomitic flat as the main sedmentary environment.While it was regression stage when the b member developed, which has made a large member of supratidal dolomite flats and gypsum-dolomite flats as favorable sedimentary facies for the development of reservoir.2.Diagenesis is the important guarantee to form favorable reservoir space.The diagenesis characteristics or Ma5-4-1 reservoir in our study area is as follows:karstification and dissolution in the supergene stage are helpful for the reservoir’s development,and the penecontemporaneous dolomitization has improved dissolution although it hasn’t formed favorable pores;compaction,pressure solution and recrystallization does no good to the reservoir’s performance.3.Tectonic evolution is a favorable factor for proceeding the diagenesis.The overlying Ordovician strata of MaS-4-1 layer in the northwest of the study area has suffered serious deletion,which is beneficial to the dissolution in both vertical and longitudinal directions by helping the infiltration of the karst water.The solution pore,fracture and intercrystalline pore are the main reservoir space types or the Ma5-4-1 layer in this area.Most of the solution pores are filled with several fillers rathe than one single filler.The packing structure is complex,but the extent is just general wih a lot of intercrystalline pores and intercrystalline solution pores left.4.The complexity of pore-structure is the microscopic embodiment of reservoir heterogeneity.The permeability of Ma5-4-1 layer is the mostly associated with porosity in the exponential function,provided by the analysis of physical property measurement.When the porosity is higher than the critical value(almost 80%),the increasing trend of permeability is very obvious as the increase of porosity.This indicates that the foundation to improve permeability is solution pores’development and the key is lies in the development of dissolution fractures and the fractures connecting pores.According to the results of high pressure mercury intrusion associated with observation of core and cast thin slic,the pore structure types has divided into five kinds,among which the a member of Ma5-4-1 is mainly of fracture-vug-pore type(account for 37%) with a accessory fracture-vug tipe(account for 21%) while the b mernber is mainly of microfracturc-microporous type and microporous type (account for 37%) with a accessory fracture-pore tipe.5.Classification evaluation of reservoir is precondition of development object blocks’ optimization.On the basis of the isoline maps’superposition combined with the distribution of sedimentary facies and the pore structure types,MaS-4-1 reservoir is divided into three types of favorable areas:typeⅠ,typeⅡand typeⅢ.The reserve-permeate performance of TypeⅠand typeⅡis better.Results of reservoir classification evaluation agree well with open flow potential of single well performance.The sum total area of typeⅠand typeⅡ has occupied 40%,while their reserves account for 60%of the total reserves in the favorable areas.Thus,typeⅠand typeⅡfavorable areas are the most prospective object blocks to explorate and exploit in the north part of Jingbian gas field.Compared with the reserve-permeate performance of Ma5-4-1 reservoir in the easten part,the northern part of Jingbian gas field has a better developing prospect.更多还原