Fracture and Gas Potential in Tight Sandstone Reservoirs in the Eastern Part of Sulige Gas Field, Ordos Basin (China)

2012 ◽  
Vol 524-527 ◽  
pp. 1236-1240
Author(s):  
Ren Chao Yang ◽  
Yi Jun Li ◽  
Tao Zhang ◽  
Ai Ping Fan ◽  
Yan Long Wang
Keyword(s):  
Natural Gas ◽  
Ordos Basin ◽  
Sem Analysis ◽  
Tight Sandstone ◽  
Gas Field ◽  
High Productivity ◽  
Distribution Laws ◽  
Sandstone Reservoirs ◽  
Gas Potential ◽  
Better Than

Sulige gas field in Ordos Basin is the largest discovered gas field in China. But tight sandstone reservoirs is becoming the main limitation of natural gas exploration and exploitation in Sulige gas field. Intensively analysis on micro-pore structure of sandstone reservoirs in Shan1 member of Shanxi formation and He8 member of Shihexizi formation in Permian system in the eastern part of Sulige gas field are conducted by means of drill core observation, slice identification, SEM analysis, casting slice and mercury injection etc. analytical methods. Result shows that fracture is well developed in sandstone reservoirs in the northern part of the interest area, by which petrophysical property of tight sandstone reservoir is improved distinctly. Types of fracture are dominated by diaclase and the diagenesis cracks. Main direction of the fractures is NE and NW, and the angle of the two groups fractures is nearly 90°.But one set of the conjugate shear fractures would develop well and the other was rest rained by the influenced of strong anisotropism of sandbodies. Diaclase and the diagenesis cracks developed along the boundery of tectonic divisions. Fracture is one of the important reasons for improvement of permeability in tight sandstone reservoirs. Gas potential of sandstone in fracture-developed section is much better than that of non-fracture section. Consequently, it is signaficant for all of reservoir forecasting, high productivity gas pool seeking, design and construction of natural gas exploitation to grasp distribution laws of fracture.

scholarly journals Microscale Pore Throat Differentiation and Its Influence on the Distribution of Movable Fluid in Tight Sandstone Reservoirs

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Fengjuan Dong ◽  
Xuefei Lu ◽  
Yuan Cao ◽  
Xinjiu Rao ◽  
Zeyong Sun
Keyword(s):  
Ordos Basin ◽  
Pore Throat ◽  
Tight Sandstone ◽  
Throat Radius ◽  
Thin Sections ◽  
Small Pore ◽  
Sandstone Reservoir ◽  
Sandstone Reservoirs ◽  
Classification Evaluation ◽  
Better Than

Tight sandstone reservoirs have small pore throat sizes and complex pore structures. Taking the Chang 6 tight sandstone reservoir in the Huaqing area of the Ordos Basin as an example, based on casting thin sections, nuclear magnetic resonance experiments, and modal analysis of pore size distribution characteristics, the Chang 6 tight sandstone reservoir in the study area can be divided into two types: wide bimodal mode reservoirs and asymmetric bimodal mode reservoirs. Based on the information entropy theory, the concept of “the entropy of microscale pore throats” is proposed to characterize the microscale pore throat differentiation of different reservoirs, and its influence on the distribution of movable fluid is discussed. There were significant differences in the entropy of the pore throat radius at different scales, which were mainly shown as follows: the entropy of the pore throat radius of 0.01~0.1 μm, >0.1 μm, and <0.01 μm decreased successively; that is, the complexity of the pore throat structure decreased successively. The correlation between the number of movable fluid occurrences on different scales of pore throats and the entropy of microscale pore throats in different reservoirs is also different, which is mainly shown as follows: in the intervals of >0.1 μm and 0.01~0.1 μm, the positive correlation between the occurrence quantity of movable fluid in the wide bimodal mode reservoir is better than that in the asymmetric bimodal mode reservoir. However, there was a negative correlation between the entropy of the pore throat radius and the number of fluid occurrences in the two types of reservoirs in the pore throat radius of <0.01 μm. Therefore, pore throats of >0.1 μm and 0.01~0.1 μm play a controlling role in studying the complexity of the microscopic pore throat structure and the distribution of movable fluid in the Chang 6 tight sandstone reservoir. The above results deepen the understanding of the pore throat structure of tight sandstone reservoirs and present guiding significance for classification evaluation, quantitative characterization, and efficient development of tight sandstone reservoirs.

Cementation and porosity evolution of tight sandstone reservoirs in the Permian Sulige gas field, Ordos Basin (central China)

2019 ◽  
Vol 103 ◽  
pp. 276-293 ◽  
Author(s):  
Aiping Fan ◽  
Renchao Yang ◽  
Nils Lenhardt ◽  
Meng Wang ◽  
Zuozhen Han ◽  
...  
Keyword(s):  
Ordos Basin ◽  
Central China ◽  
Tight Sandstone ◽  
Gas Field ◽  
Porosity Evolution ◽  
Sandstone Reservoirs

A New Method to Predict Favorable Gas-Rich Area in Tight Sandstone Gas Reservoir in Daniudi Area

2013 ◽  
Vol 295-298 ◽  
pp. 3328-3332
Author(s):  
Hai Ying Han ◽  
Zhi Zhang Wang ◽  
Xin Xiao Sun ◽  
Wei Jun Wang
Keyword(s):  
Ordos Basin ◽  
Gas Reservoirs ◽  
Tight Sandstone ◽  
Gas Reservoir ◽  
Gas Field ◽  
High Productivity ◽  
Integrated Method ◽  
Geological Information ◽  
Sedimentary Microfacies ◽  
Developing Area

Daniudi gas field is a tight sandstone gas field in the northeast of Ordos Basin. How to use the successful experience in developing area to predict favorable gas-rich area in other areas in this gas field is very important to the next exploration and development in this field. This paper proposes a multi-information integrated method to predict favorable gas-rich area. Firstly describe sedimentary microfacies by integrating seismic, logging and geological information; and then summarize and analyze the seismic reflection patterns of medium-high productivity wells; finally determine the favorable gas-rich area with the distribution of storage coefficient based on the previous analysis. The welltest of newly drilled wells shows that the coincidence rate of favorable gas-rich area predicted by this method could be up to 90%,and this method could be extended to use in the other tight sandstone gas reservoirs.

scholarly journals Impact of Differential Densification on the Pore Structure of Tight Gas Sandstone: Evidence from the Permian Shihezi and Shanxi Formations, Eastern Sulige Gas Field, Ordos Basin, China

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-25
Author(s):  
Meng Wang ◽  
Hongming Tang ◽  
Haoxuan Tang ◽  
Shu Liu ◽  
Liehui Zhang ◽  
...  
Keyword(s):  
Pore Space ◽  
Ordos Basin ◽  
Environmental Scanning Electron Microscopy ◽  
Homogenization Temperature ◽  
Middle Part ◽  
Tight Sandstone ◽  
Gas Field ◽  
Thin Sections ◽  
Reservoir Development ◽  
Sandstone Reservoirs

The tight sandstone reservoirs of the Permian Shihezi and Shanxi Formation with strong heterogeneity constitute the main producing zone of the eastern Sulige gas field. The process of differential densification results in various reservoir qualities. Mineral composition, structural characteristic, pore system, and diagenesis were investigated with analyses of well logs, thin sections, porosity, and horizontal permeability of the core plugs; environmental scanning electron microscopy (ESEM); nuclear magnetic resonance (NMR); X-ray computed tomography (X-CT); and fluid inclusion homogenization temperature. The results show that lithic sandstone reservoirs experienced complex and various diagenetic evolutions. Eight types of densification modes can be divided according to the diagenesis paths; these modes represent lithofacies with different densification times and reservoir qualities. Intense mechanical compaction is the main reason for the formation of lithofacies 1, 2, and 5. Lithofacies 4, 6, and 7 formed due to intense cementation, increasing the impermeability of the diagenetic system. The primary pore space in lithofacies 3 is preserved due to the overpressure and chlorite coatings. The dissolution and weak cementation of lithofacies 8 contribute to reservoir development. The middle-lower part of braided channel lags and channel bars, the middle part of meandering riverbed lags, and the middle part of point bars are favourable for reservoir development.

scholarly journals Hydrocarbon geochemistry and charging history of the deep tight sandstone reservoirs in the Dabei Gas Field, Kuqa Depression, Tarim Basin, NW China

2020 ◽  
Vol 38 (6) ◽  
pp. 2325-2355
Author(s):  
Qiang Wei ◽  
Xianqing Li ◽  
Kexin Sun ◽  
Guangwu Zhang ◽  
Wanle Liang ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Natural Gas ◽  
Source Rocks ◽  
Tight Sandstone ◽  
Gas Field ◽  
Kuqa Depression ◽  
Natural Gases ◽  
History Of ◽  
Sandstone Reservoir ◽  
Sandstone Reservoirs

The geochemical feature and evolutionary history of hydrocarbons from the deep Cretaceous Bashijiqike (K1 bs) Formation tight sandstone reservoir in the Dabei Gas Field, Kuqa Depression were investigated using gas chromatography, gas chromatography–mass spectrometry, inclusions petrography and micro-thermometry, laser Raman spectroscopy, and quantitative grain fluorescence. The result indicates that natural gases from the deep sandstone reservoir are mainly composed of alkanes and belong to dry gases, of which methane accounts for 94.30–97.20% (avg. 95.64%), and ethane is 1.23–2.45% (avg. 1.95%). The stable carbon isotopic value of methane and ethane is −31.9‰ to −29.3‰ (avg. −30.3‰) and −24.2‰ to −19.4‰ (avg. −21.7‰), respectively, and this reflects the features of high-mature coal-derived gases. In addition, natural gases in the Dabei Gas Field have characteristics of coal-derived gases which were sourced from Jurassic coal measures. Oils in the Dabei Gas Field predominately originated from Triassic Huangshanjie (T3 h) Formation mudstones with some contributions from Jurassic coaly rocks. Petrological and micro-thermometry results of fluid inclusions suggest that the K1 bs Formation tight sandstone reservoirs have experienced two phases of hydrocarbons charge histories, namely “early oil and later gas.” The quantitative grain fluorescence analysis indicated that sandstone samples with quantitative grain fluorescence index value >5 and quantitative grain fluorescence-extraction intensity >40 pc in Wells DB101 and DB2 can be used as indicators for the paleo oil layers or the migration channels of later charged natural gas. The aforementioned analyses and burial and thermal histories of K1 bs sandstone reservoir demonstrated that oil charged at 10 Ma and natural gas charged at approximately 3 Ma in the study area. Furthermore, paleo-tectonic evolution enabled source rocks to mature and expel hydrocarbons, and the structurally related faults and traps provided pathways and places for hydrocarbon migration and accumulation.

Sign in / Sign up

Export Citation Format

Share Document