Numerical Simulation of Stimulated Volume in Low-Permeability Reservoir

2013 ◽  
Vol 734-737 ◽  
pp. 1415-1419
Author(s):  
Zhen Yu Liu ◽  
Tian Tian Cai ◽  
Hu Zhen Wang ◽  
Cheng Yu Zhang
Keyword(s):  
Numerical Simulation ◽  
Reference Value ◽  
Simulation Method ◽  
Fracture Network ◽  
Gas Production ◽  
Low Permeability ◽  
Flow State ◽  
Low Permeability Reservoir ◽  
Complex Fracture ◽  
Low Permeability Reservoirs

There is an increasing focus on the effective methods to develop low-permeability reservoirs, especially for ultra-low permeability reservoirs. It is hard to achieve the expected stimulation effect only on the traditional single fracturing, because of the poor supply ability from the matrix to fracture in low-permeability reservoirs. Volume stimulating to reservoir, achieving short distance from matrix to fracture because of producing fracture network. So the volume fracturing technology proposed for increasing oil or gas production, this technology is suitable for low porosity and low permeability reservoir. The conventional simulation method can't describe the complex fracture network accurately,but this paper established hydraulic fracturing complex fracture model based on the finite element numerical simulation method , making the simulated complex fracture more close to the real description,it can accurately describe the flow state in the reservoir and cracks.It has an important reference value to the low permeability reservoirs.

A Study of Seepage Characteristics of Unsteady Waterflooding Development for Fractured Ultra-Low-Permeability Reservoir

2021 ◽  
Author(s):  
Qing Liu ◽  
Xiangfang Li ◽  
Jian Yang ◽  
Sen Feng ◽  
Minxia He ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Simulation Model ◽  
Water Injection ◽  
Injection Rate ◽  
Low Permeability ◽  
Tensor Model ◽  
Capillary Imbibition ◽  
Low Permeability Reservoir ◽  
Water Cut ◽  
Low Permeability Reservoirs

Abstract Unconventional fractured ultra-low-permeability reservoirs play an important role in continental sedimentary basins in China, and their formation characteristics and seepage laws are greatly different from that of traditional reservoirs. In this paper, the influence of microfractures and unsteady waterflooding on the productivity of fractured ultra-low permeability reservoirs are studied deeply. The reservoir parameters used in the study are from an actual fractured ultra-low-permeability reservoir in Ordos Basin, where microfractures are developed but macroscopic fractures are not. The microfractures have a small opening and are widely distributed in the reservoir, so the reservoir numerical simulation model adopts the equivalent continuous matrix model to simulate waterflooding. On one hand, the physical model of micro-fractured reservoir and the permeability tensor model of the equivalent continuous matrix are established. The results show that the existence of microfractures can increase the permeability of matrix by 1.4 times. On the other hand, an ideal heterogeneous numerical simulation model composed of pure matrix and equivalent continuous matrix considering microfracture is established according to actual geological parameters of the fractured ultra-low-permeability reservoir. To simulate and compare the unsteady waterflooding and continuous waterflooding development in 10-year development under the condition of constant annual injection rate, the results indicate that unsteady waterflooding development make higher productivity and lower water cut and lower formation water saturation than that of continuous waterflooding. By conducting unsteady waterflooding development simulation for sensitivity analysis, the results demonstrate that the greater the capillary force, the better the role of capillary imbibition in a certain range, meanwhile, the unsteady waterflooding has the best exploitation effect when the value of water injection cycle time is 100 days and the fluctuation amplitude of water injection rate is 1. At the above situation, the displacement and capillary imbibition and pressure disturbance achieve the desired effect of reducing water cut and increasing oil production.

scholarly journals The Research of Capillary Pressure in the Process of CO Displacement in Low-Permeability Reservoir

2015 ◽  
Vol 8 (1) ◽  
pp. 248-252
Author(s):  
Li Jiqiang ◽  
Huang Xiaoliang ◽  
Niu Xiaofeng ◽  
Yuan Yingzhong ◽  
Yan Wende
Keyword(s):  
Numerical Simulation ◽  
Capillary Pressure ◽  
Driving Force ◽  
Component Model ◽  
Resistance Force ◽  
Low Permeability ◽  
One Dimensional ◽  
Low Permeability Reservoir ◽  
Displacement Experiments ◽  
Low Permeability Reservoirs

The function of capillary pressure in the process of CO displacement in low-permeability reservoir is researched through combination of indoor experiments and numerical simulation. On the basis of different displacement experiments in long core chamber, one-dimensional numerical simulation component model is built to research the function of capillary pressure under the different CO displacement ways. The results show that the capillary pressure under the different CO displacement ways is not consistent. Capillary pressure is the driving force in the process of CO displacement while resistance force in the process of CO pressure buildup and displacement. In order to promote reasonable and efficient development of low-permeability reservoirs, it is suggested that further study about microscopic effects and laws of the capillary pressure in the reservoir should be done through experiment.

The Study of Flowing Law of Typical well Patterns in Low Permeability Reservoirs

2013 ◽  
Vol 444-445 ◽  
pp. 338-341 ◽  
Author(s):  
Shu Ren Yang ◽  
Bi Yi Li
Keyword(s):  
Horizontal Well ◽  
Cost Effective ◽  
Simulation Method ◽  
Low Permeability ◽  
Low Permeability Reservoir ◽  
Well Pattern ◽  
Key Issues ◽  
Flow Law ◽  
Effective Development ◽  
Low Permeability Reservoirs

Low permeability reservoirs have abundant reserves, accounting for about one-third of all the reservoir storage, but the development is difficult and the recovery is low because of its poor natural property. Reasonable well pattern, well pattern parameters and fracture parameters can be effective in improving the development of low-permeability reservoir. Therefore, studying flow law of various well networks, choosing a reasonable well pattern and corresponding well parameters, are key issues of cost-effective development of low permeability reservoir. Based on extensive investigations of former researches, this paper studies the flow law of vertical well patterns and the effect of permeability differential on flow law. Adaptive study of those different kinds of well patterns has been done by numerical simulation method, including the five point well pattern, inverted seven point well pattern and the inverted nine point well pattern. Studying the typical horizontal well pattern on the flow law, comparing the characteristics of the streamlines. Choosing a reasonable form of well pattern and the well pattern parameters.

The Seepage Pressure Distribution and the Capacity of Low-Permeability Reservoirs Gas

2013 ◽  
Vol 734-737 ◽  
pp. 1317-1323
Author(s):  
Liang Dong Yan ◽  
Zhi Juan Gao
Keyword(s):  
Mathematical Model ◽  
Pressure Distribution ◽  
Low Permeability ◽  
Flow State ◽  
Klinkenberg Effect ◽  
Gas Reservoirs ◽  
Gas Well ◽  
Seepage Pressure ◽  
Slippage Effect ◽  
Low Permeability Reservoirs

Low-permeability gas reservoirs are influenced by slippage effect (Klinkenberg effect) , which leads to the different of gas in low-permeability and conventional reservoirs. According to the mechanism and mathematical model of slippage effect, the pressure distribution and flow state of flow in low-permeability gas reservoirs, and the capacity of low-permeability gas well are simulated by using the actual production datum.

Numerical Simulation Study on the Key Influencing Factors of Water-Invasion Performance for the Gas Wells with Bottom-Water

2014 ◽  
Vol 884-885 ◽  
pp. 104-107
Author(s):  
Zhi Jun Li ◽  
Ji Qiang Li ◽  
Wen De Yan
Keyword(s):  
Numerical Simulation ◽  
Influencing Factors ◽  
Bottom Water ◽  
Simulation Method ◽  
Gas Production ◽  
Production Performance ◽  
Gas Wells ◽  
Two Phase ◽  
Gas Well ◽  
Water Gas

For the water-sweeping gas reservoir, especially when the water-body is active, water invasion can play positive roles in maintaining formation pressure and keeping the gas well production. But when the water-cone break through and towards the well bottom, suffers from the influencing of gas-water two phase flows, permeability of gas phase decrease sharply and will have a serious impact on the production performance of the gas well. Moreover, the time when the water-cone breakthrough will directly affect the final recovery of the gas wells, therefore, the numerical simulation method is used to conduct the research on the key influencing factors of water-invasion performance for the gas wells with bottom-water, which is the basis of the mechanical model for the typical gas wells with bottom-water. It indicate that as followings: (1) the key influencing factors of water-invasion performance for the gas wells with bottom-water are those, such as the open degree of the gas beds, well gas production and the amount of Kv/Kh value; and (2) the barrier will be in charge of great significance on the water-controlling for the bottom water gas wells, and its radius is the key factor to affect water-invasion performance for the bottom water gas wells where the barriers exist nearby.

Numerical Simulation for Shale Gas Flow in Complex Fracture System of Fractured Horizontal Well

2018 ◽  
Vol 19 (3-4) ◽  
pp. 367-377 ◽  
Author(s):  
Yingzhong Yuan ◽  
Wende Yan ◽  
Fengbo Chen ◽  
Jiqiang Li ◽  
Qianhua Xiao ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Shale Gas ◽  
Horizontal Well ◽  
Fracture Network ◽  
Gas Reservoir ◽  
Complex Fracture ◽  
Shale Gas Reservoir ◽  
Fracture Parameters ◽  
Fracture Systems ◽  
Fractured Horizontal Well

AbstractComplex fracture systems including natural fractures and hydraulic fractures exist in shale gas reservoir with fractured horizontal well development. The flow of shale gas is a multi-scale flow process from microscopic nanometer pores to macroscopic large fractures. Due to the complexity of seepage mechanism and fracture parameters, it is difficult to realize fine numerical simulation for fractured horizontal wells in shale gas reservoirs. Mechanisms of adsorption–desorption on the surface of shale pores, slippage and Knudsen diffusion in the nanometer pores, Darcy and non-Darcy seepage in the matrix block and fractures are considered comprehensively in this paper. Through fine description of the complex fracture systems after horizontal well fracturing in shale gas reservoir, the problems of conventional corner point grids which are inflexible, directional, difficult to geometrically discretize arbitrarily oriented fractures are overcome. Discrete fracture network model based on unstructured perpendicular bisection grids is built in the numerical simulation. The results indicate that the discrete fracture network model can accurately describe fracture parameters including length, azimuth and density, and that the influences of fracture parameters on development effect of fractured horizontal well can be finely simulated. Cumulative production rate of shale gas is positively related to fracture half-length, fracture segments and fracture conductivity. When total fracture length is constant, fracturing effect is better if single fracture half-length or penetration ratio is relatively large and fracturing segments are moderate. Research results provide theoretical support for optimal design of fractured horizontal well in shale gas reservoir.

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