CAJ | 학술논문

鄂尔多斯盆地子洲气田山23段砂岩为一套典型的低孔、低渗储层，平均孔隙度为4.94%，平均渗透率为0.78×10-3μm2，主要孔隙类型为残余粒间孔、溶蚀孔和晶间孔，孔隙结构以中粗孔径-细喉道为主。山23致密砂岩储层经历了复杂的成岩作用，如压实、胶结、压溶等作用，其中压实和胶结等破坏性成岩作用使储层的原生孔隙大大减少，使储层的孔隙度和渗透率降低，导致储层变得致密。研究表明，沉积环境是控制致密砂岩储层形成的基本因素，填隙物含量对储层物性有重要影响，随着填隙物含量的增加，储层物性逐渐变差，而成岩作用对储层的致密化起决定性作用，其中三角洲前缘砂体中的水下分流河道砂体物性最好，而且主砂体展布带内中心部位物性相对较好，向两边逐渐变差。
악이다사분지자주기전산23단사암위일투전형적저공、저삼저층，평균공극도위4.94%，평균삼투솔위0.78×10-3μm2，주요공극류형위잔여립간공、용식공화정간공，공극결구이중조공경-세후도위주。산23치밀사암저층경력료복잡적성암작용，여압실、효결、압용등작용，기중압실화효결등파배성성암작용사저층적원생공극대대감소，사저층적공극도화삼투솔강저，도치저층변득치밀。연구표명，침적배경시공제치밀사암저층형성적기본인소，전극물함량대저층물성유중요영향，수착전극물함량적증가，저층물성축점변차，이성암작용대저층적치밀화기결정성작용，기중삼각주전연사체중적수하분류하도사체물성최호，이차주사체전포대내중심부위물성상대교호，향량변축점변차。
Shang23 sandstone in Zizhou gas field of Ordos Basin is a typical reservoir with low porosity and permeability. Its average porosity is 4.94 % and its average permeability is 0.78×10-3μm2. The main pore types are residual inter-granular pore, dissolved pore and inter-crystalline pore. The main pore structure is medium coarse aperture and thin throat. The Shang23 tight reservoir has experienced complex diagenesis, such as compaction, cementation and dissolution. The destructive diagenesis of compaction and cementation sharply reduce the primary pores of the reservoir so as to lower the porosity and permeability, which result in the tight-ness of the reservoir. According to the researches, depositional environment is the basic controlling factor of the formation of the tight sandstone reservoir, and interstitial matter has an important influence on the physical property of the reservoir, with the in-creasing of which the physical property get poorer. Diagenesis is the determining factor in reservoir tightening, while the underwa-ter distributary channel sands in delta front have the best physical property, and the central part of the sand body is better than the side parts.