Optimization of Fracture Parameters for Hydraulic Fractured Horizontal Well in a Heterogeneous Tight Reservoir: An Equivalent Homogeneous Modelling Approach

Abstract

Building numerical reservoir simulation model with a view to model actual case requires enormous amount of data and information. Such modeling and simulation processes normally require lengthy time and different sets of field data and experimental tests that are usually very expensive. In addition, the availability, quality and accessibility of all necessary data are very limited, especially for the green field. The degree of complexities of such modelling increases significantly especially in the case of heterogeneous nature typically inherited in unconventional reservoirs. In this perspective, this study focuses on exploring the possibility of simplifying the numerical simulation process without compromising the accuracy of results for heterogeneous unconventional tight gas reservoir with an emphasis on optimisation of multi-stage hydraulic fractured parameters, such as fracture half-length and number of fractures towards maximization the net present value (NPV). The key objectives of this study are to mitigate the effect of reservoir heterogeneity through building an equivalent simplified homogeneous reservoir simulation model for forecasting the production performance of fractured horizontal well in a heterogeneous carbonate tight gas reservoir and optimize the fracture parameters such as number of fractures and fracture half-length based on maximizing the NPV. The homogeneous model, which is equivalent to a heterogeneous reservoir model was built based on the statistical analysis of the rock properties of heterogeneous model. The simulation results obtained were analysed for a number of cases covering a range of fracture number (from 1 to 80), fracture half-length (from 500 to 2000 ft). The result demonstrated that the simplified equivalent homogeneous model has the ability to provide a good estimate for production forecasting, and determine the optimum number of fractures and fracture half-length within a high accuracy. The model is simple, yet provides good approximation with high accuracy, but save huge computation time.

Effect of Geological Heterogeneity on the Production Performance of a Multifractured Horizontal Well in Tight Gas Reservoirs

“…Compared to the analytical and semianalytical methods, the numerical simulation methods are more convenient to study the transient flow and production problems in both homogeneous and heterogeneous reservoirs [19][20][21][22][23][24][25][26][27][28][29]. Yu et al [19] discussed the effect of different fracture half-length combinations on the multifractured gas well production performance.…”

“…Subsequently, a large number of interpretation results were used as input variables in the simulation. Al-Fatlawi et al [29] proposed a method to optimize multistage hydraulic fractured parameters by using a homogeneous model instead of a heterogeneous model in a heterogeneous tight gas reservoir.…”

Construction of Comprehensive Geological Model for an Iraqi Oil Reservoir

“…A 3D model is a mathematical illustration developed by the special platform for any threedimensional object (Dheyauldeen et al, 2021, Al-Fatlawi et al, 2019a, Al-Fatlawi, 2018, King and Mansfield, 1997. The geological model spatially embodies the underground sediments and rocks distribution.…”

Estimate Gas Initially in Place of Tight Gas Reservoirs Based on Developed Methodology of Dynamic Material Balance Technique

“…The petroleum industry is quickly depleting conventional resources whilst worldwide demand for hydrocarbons continues to grow (Sadeq, 2018, Al-Fatlawi et al, 2019a, Al-Fatlawi et al, 2019b. To deliver this rising demand, the industry is beginning to develop technologies and techniques to improve economic viability of unconventional reservoirs.…”

“…• Decline curve analysis Numerical reservoir simulation is commonly regarded as the most precise form of GIIP estimation (Al-Fatlawi et al, 2019a) however requires a significant data set and extrapolation between wells and reservoir boundaries (Al-Fatlawi, 2018, Dheyauldeen et al, 2021. Tight gas reservoirs (TGRs) modelling can be a complicated expensive mission due to severe heterogeneities and uncertainties tied to reservoir parameters such as porosity and permeability providing a range of variable when history matching.…”