Horizontal Well Transient Pressure Testing in Coalbed Reservoirs

1994 ◽  
Author(s):  
P. Sarkar ◽  
J. Rajtar
Keyword(s):  
Horizontal Well ◽  
Transient Pressure ◽  
Pressure Testing

A Semianalytical Model for Predicting Transient Pressure Behavior of a Hydraulically Fractured Horizontal Well in a Naturally Fractured Reservoir With Non-Darcy Flow and Stress-Sensitive Permeability Effects

SPE Journal ◽  
2019 ◽  
Vol 24 (03) ◽  
pp. 1322-1341 ◽  
Author(s):  
Liwu Jiang ◽  
Tongjing Liu ◽  
Daoyong Yang
Keyword(s):  
Mathematical Models ◽  
Horizontal Well ◽  
Flow Behavior ◽  
Stress Sensitivity ◽  
Darcy Flow ◽  
Combined Effects ◽  
Fractured Reservoir ◽  
Transient Pressure ◽  
Linear Flow ◽  
Fractured Horizontal Well

Summary Non-Darcy flow and the stress-sensitivity effect are two fundamental issues that have been widely investigated in transient pressure analysis for fractured wells. The main object of this work is to establish a semianalytical solution to quantify the combined effects of non-Darcy flow and stress sensitivity on the transient pressure behavior for a fractured horizontal well in a naturally fractured reservoir. More specifically, the Barree-Conway model is used to quantify the non-Darcy flow behavior in the hydraulic fractures (HFs), while the permeability modulus is incorporated into mathematical models to take into account the stress-sensitivity effect. In this way, the resulting nonlinearity of the mathematical models is weakened by using Pedrosa's transform formulation. Then a semianalytical method is applied to solve the coupled nonlinear mathematical models by discretizing each HF into small segments. Furthermore, the pressure response and its corresponding derivative type curve are generated to examine the combined effects of non-Darcy flow and stress sensitivity. In particular, stress sensitivity in HF and natural-fracture (NF) subsystems can be respectively analyzed, while the assumption of an equal stress-sensitivity coefficient in the two subsystems is no longer required. It is found that non-Darcy flow mainly affects the early stage bilinear and linear flow regime, leading to an increase in pressure drop and pressure derivative. The stress-sensitivity effect is found to play a significant role in those flow regimes beyond the compound-linear flow regime. The existence of non-Darcy flow makes the effect of stress sensitivity more remarkable, especially for the low-conductivity cases, while the stress sensitivity in fractures has a negligible influence on the early time period, which is dominated by non-Darcy flow behavior. Other parameters such as storage ratio and crossflow coefficient are also analyzed and discussed. It is found from field applications that the coupled model tends to obtain the most-reasonable matching results, and for that model there is an excellent agreement between the measured and simulated pressure response.

scholarly journals Pressure Transient Performance for a Horizontal Well Intercepted by Multiple Reorientation Fractures in a Tight Reservoir

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4232 ◽  
Author(s):  
Guoqiang Xing ◽  
Shuhong Wu ◽  
Jiahang Wang ◽  
Mingxian Wang ◽  
Baohua Wang ◽  
...  
Keyword(s):  
Horizontal Well ◽  
Flow Behavior ◽  
Flow Equation ◽  
Finite Conductivity ◽  
Transient Pressure ◽  
Pressure Derivative ◽  
Fracture Conductivity ◽  
Fracture Spacing ◽  
Economic Production ◽  
Tight Reservoir

A fractured horizontal well is an effective technology to obtain hydrocarbons from tight reservoirs. In this study, a new semi-analytical model for a horizontal well intercepted by multiple finite-conductivity reorientation fractures was developed in an anisotropic rectangular tight reservoir. Firstly, to establish the flow equation of the reorientation fracture, all reorientation fractures were discretized by combining the nodal analysis technique and the fracture-wing method. Secondly, through coupling the reservoir solution and reorientation fracture solution, a semi-analytical solution for multiple reorientation fractures along a horizontal well was derived in the Laplace domain, and its accuracy was also verified. Thirdly, typical flow regimes were identified on the transient-pressure curves. Finally, dimensionless pressure and pressure derivative curves were obtained to analyze the effect of key parameters on the flow behavior, including fracture angle, permeability anisotropy, fracture conductivity, fracture spacing, fracture number, and fracture configuration. Results show that, for an anisotropic rectangular tight reservoir, horizontal wells should be deployed parallel to the direction of principal permeability and fracture reorientation should be controlled to extend along the direction of minimum permeability. Meanwhile, the optimal fracture number should be considered for economic production and the fracture spacing should be optimized to reduce the flow interferences between reorientation fractures.

Transient pressure analysis of horizontal well in low permeability oil reservoir

2015 ◽  
Vol 10 (1) ◽  
pp. 23
Author(s):  
Yu Long Zhao ◽  
Lie Hui Zhang ◽  
Jin Zhou Zhao ◽  
Shu Yong Hu ◽  
Bo Ning Zhang
Keyword(s):  
Horizontal Well ◽  
Low Permeability ◽  
Oil Reservoir ◽  
Transient Pressure ◽  
Transient Pressure Analysis ◽  
Pressure Analysis

scholarly journals Transient Pressure and Rate Decline Analysis for Horizontal Well in Stress-Sensitive Composite Reservoir

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Yu Huang ◽  
Xiaoping Li ◽  
Xiaohua Tan
Keyword(s):  
Horizontal Well ◽  
Transient Flow ◽  
Orthogonal Transformation ◽  
Flow Analysis ◽  
Analytic Solutions ◽  
Stress Sensitivity ◽  
Transient Pressure ◽  
Regular Perturbation ◽  
Transient Flow Analysis ◽  
Permeability Modulus

The existence of stress sensitivity effect made the percolation mechanism of low-permeability reservoirs significantly complex. Further, numerous reservoirs have composite stratum properties in actual development procedure. This paper based on the concept of permeability stress sensitivity presents an unsteady flow model for horizontal well taking both stress sensitivity and composite reservoir into account. Analytic solutions for the transient pressure and the rate decline behaviors are obtained by comprehensive utilization of regular perturbation method, Laplace transformation, orthogonal transformation, and Stehfest numerical inversion. The example analysis verifies that the proposed model is reliable and practical. Likewise, there is a discussion of the influence of permeability modulus and other relevant parameters on the transient pressure and the rate decline for horizontal well in stress-sensitive composite reservoir. The work of this paper improved the previous researches and provided a more accurate basis for transient flow analysis and formation evaluation of this typical reservoir.

Transient pressure analysis of a horizontal well with multiple, arbitrarily shaped horizontal fractures

2019 ◽  
Vol 180 ◽  
pp. 631-642 ◽  
Author(s):  
Hongyang Chu ◽  
Xinwei Liao ◽  
Zhiming Chen ◽  
Xiaoliang Zhao ◽  
Wenyuan Liu ◽  
...  
Keyword(s):  
Horizontal Well ◽  
Transient Pressure ◽  
Transient Pressure Analysis ◽  
Pressure Analysis

scholarly journals Semianalytical Coupled Model of Transient Pressure Behavior for Horizontal Well with Complex Fracture Networks in Tight Oil Reservoirs

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Ren Zongxiao ◽  
Du Kun ◽  
Shi Junfeng ◽  
Liu Wenqiang ◽  
Qu Zhan ◽  
...  
Keyword(s):  
Horizontal Well ◽  
Variable Mass ◽  
Fracture Network ◽  
Fracture Networks ◽  
Transient Pressure ◽  
Pressure Behavior ◽  
Complex Fracture ◽  
Complex Fracture Network ◽  
Horizontal Wellbore ◽  
Seepage Model

Due to a large number of natural fractures in tight oil reservoir, many complex fracture networks are generated during fracturing operation. There are five kinds of flow media in the reservoir: “matrix, natural fracture, hydraulic fracture network, perforation hole, and horizontal wellbore”. How to establish the seepage model of liquid in multiscale medium is a challenging problem. Firstly, this paper establishes the dual medium seepage model based on source function theory, principle of superposition, and Laplace transformation and then uses the “star-triangle” transform method to establish the transient pressure behavior model in the complex fracture network. After that, perforating seepage model and variable mass flow in horizontal wellbore were established. Finally, continuous condition was used to couple the seepage model of dual medium seepage model, transient pressure behavior model in the complex fracture network, perforation seepage model, and the variable mass seepage model in horizontal wellbore, to establish a semianalytical coupled seepage model for horizontal well in tight reservoir. This paper provides theoretical basis for field application of horizontal well with complex fracture networks.

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