Study on Well Pattern Optimization of Tight Sandstone Gas Reservoir with the Strong Heterogeneity

2013 ◽  
Author(s):  
Ji Zhang ◽  
Tao Lu ◽  
Yuegang Li ◽  
Shuming Yu ◽  
Jingbu Li ◽  
...  
2021 ◽  
Vol 11 (8) ◽  
pp. 3301-3310
Author(s):  
Mingze Gong ◽  
Jinliang Zhang ◽  
Zhaoxun Yan ◽  
Jinkai Wang

AbstractSulige gas field has poor reservoir physical properties and strong heterogeneity. The existing development well pattern is difficult to realize the overall effective production of reserves, especially in block SuX. Therefore, this paper takes SuX block in the east of Sulige as an example to describe an effective method suitable for the development of well pattern in this area. Combined with logging and production data, the connectivity of gas wells in X infill area in the east of Sulige is determined from the aspects of pressure, sand body, logging, performance and well test. By using the method of dynamic and static analysis, the connectivity between wells of main gas reservoir is judged. Through the analysis of flow unit, the discharge area and the stable value of well-controlled reserves are determined. The degree of interference determined by curve fitting and the distribution characteristics of sand bodies are comprehensively analyzed. A new oil well interference degree model defined by mathematical expression of production is established. The interference degree is quantified by gas production through numerical simulation. Based on the comprehensive analysis of the connectivity, interference degree and other factors in the area, it is determined that 500 * 600 well pattern is a reasonable well pattern in SuX block, and the interference degree is about 20%. Based on the analysis of the connectivity between wells and the interference degree between production wells in SuX block, the distribution and connectivity of sand bodies in tight sandstone gas field under complex geological conditions are determined. It provides a reasonable basis for the network encryption development of tight sandstone gas in this block. It provides a powerful technical support for the efficient development of different tight gas reservoirs in Sulige area.


Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Minhua Cheng ◽  
Wen Xue ◽  
Meng Zhao ◽  
Guoting Wang ◽  
Bo Ning ◽  
...  

Successful exploitation of tight sandstone gas is one of the important means to ensure the “increasing reserves and production” of the oil and gas initiative and also one of the important ways to ensure national energy security. To further improve the accuracy of historical matching of field data such as gas production and bottom-hole pressure during the production process of this type of gas reservoir, in this study, a new expression of wellbore pressure for the uniform flow of vertical fractured wells in Laplace space based on the point sink function model of vertical fractures in tight sandstone gas reservoirs is constructed. This innovation is based on a typical production data analysis plot of the Blasingame type that uses the numerical inversion decoupling mathematical equation. After analyzing the pressure and pressure derivative characteristics of each flow stage in the typical curves, a new technique of type-curve matching was proposed. In order to verify the correctness of the model and the application value of the field, based on the previous production data of Sulige Gas Field in China, a new set of production data diagnostic chart of tight sandstone gas reservoir was formed. A case analysis showed that the application of the production data analysis method and data diagnosis plot in the field accurately evaluated the development effect of the tight sandstone gas reservoirs, clarified the scale of effective sand bodies, and provided technical support for optimizing and improving the well pattern and realizing the efficient development of gas fields.


Energy ◽  
2020 ◽  
Vol 209 ◽  
pp. 118449
Author(s):  
Tao Zhang ◽  
Lei Zhang ◽  
Yongke Wang ◽  
Xiangyang Qiao ◽  
Dong Feng ◽  
...  

2021 ◽  
Author(s):  
Jiaying Li ◽  
Chunyan Qi ◽  
Ye Gu ◽  
Yu Ye ◽  
Jie Zhao

Abstract The characteristics of seepage capability and rock strain during reservoir depletion are important for reservoir recovery, which would significantly influence production strategy optimization. The Cretaceous deep natural gas reservoirs in Keshen Gasfield in Tarim Basin are mainly buried over 5000 m, featuring with ultra-low permeability, developed natural fractures and complex in-situ stress states. However, there is no comprehensive study on the variation of mechanical properties and seepage capability of this gas reservoir under in-situ stress conditions and most studies on stress-sensitivity are conducted under conventional triaxial or uniaxial stress conditions, which cannot truly represent in-situ stress environment. In this work, Cretaceous tight sandstone in Keshen Gasfield was tested under true-triaxial stresses conditions by an advanced geophysical imaging true-triaxial testing system to study the stress-sensitivity and anisotropy of rock stress-strain behavior, porosity and permeability. Four groups of sandstone samples are prepared as the size of 80mm×80mm×80mm, three of which are artificially fractured with different angle (0°,15°,30°) to simulate hydraulic fracturing. The test results corresponding to different samples are compared to further reveal the influence of the fracture angle on rock mechanical properties and seepage capability. The samples are in elastic strain during reservoir depletion, showing an apparent correlation with fracture angles. The porosity decreases linearly with stress loading, where the decrease rate of effective porosity of fracture samples is significantly higher than that of intact samples. The permeabilities decrease exponentially and show significant anisotropy in different principal stress directions, especially in σH direction. The mechanical properties and seepage capability of deep tight sandstone are successfully tested under true-triaxial stresses conditions in this work, which reveals the stress-sensitivity of anisotropic permeability, porosity and stress-strain behavior during gas production. The testing results proposed in this paper provides an innovative method to analyse rock mechanical and petrophysical properties and has profound significance on exploration and development of tight gas reservoir.


2016 ◽  
Vol 20 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Jinxian He ◽  
Xiaoli Zhang ◽  
Li Ma ◽  
Hongchen Wu ◽  
Muhammad Ashraf

<p>There are enormous resources of unconventional gas in coal measures in Ordos Basin. In order to study the geological characteristics of unconventional gas in coal Measures in Ordos Basin, we analyzed and summarized the results of previous studies. Analysis results are found that, the unconventional gas in coal measures is mainly developed in Upper Paleozoic in Eastern Ordos Basin, which including coalbed methane, shale gas and tight sandstone gas. The oil and gas show active in coal, shale and tight sandstone of Upper Paleozoic in Ordos Basin. Coalbed methane reservoir and shale gas reservoir in coal measures belong to “self-generation and self- preservation”, whereas the coal measures tight sandstone gas reservoir belongs to “allogenic and self-preservation”. The forming factors of the three different kinds of gasses reservoir are closely related and uniform. We have the concluded that it will be more scientific and reasonable that the geological reservoir-forming processes of three different kinds of unconventional gas of coal measures are studied as a whole in Ordos Basin, and at a later stage, the research on joint exploration and co-mining for the three types of gasses ought to be carried out.</p>


Author(s):  
Zhijun Liu ◽  
Zhenglin Mao ◽  
Haobo Zhang ◽  
Yongbin Zhang ◽  
Qian Liu ◽  
...  

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Yongchao Xue ◽  
Qingshuang Jin ◽  
Hua Tian

Finding ways to accelerate the effective development of tight sandstone gas reservoirs holds great strategic importance in regard to the improvement of consumption pattern of world energy. The pores and throats of the tight sandstone gas reservoir are small with abundant interstitial materials. Moreover, the mechanism of gas flow is highly complex. This paper is based on the research of a typical tight sandstone gas reservoir in Changqing Oilfield. A strong stress sensitivity in tight sandstone gas reservoir is indicated by the results, and it would be strengthened with the water production; at the same time, a rise to start-up pressure gradient would be given by the water producing process. With the increase in driving pressure gradient, the relative permeability of water also increases gradually, while that of gas decreases instead. Following these results, a model of gas-water two-phase flow has been built, keeping stress sensitivity, start-up pressure gradient, and the change of relative permeability in consideration. It is illustrated by the results of calculations that there is a reduction in the duration of plateau production period and the gas recovery factor during this period if the stress sensitivity and start-up pressure gradient are considered. In contrast to the start-up pressure gradient, stress sensitivity holds a greater influence on gas well productivity.


Sign in / Sign up

Export Citation Format

Share Document