Investigating the pressure characteristics and production performance of liquid-loaded horizontal wells in unconventional gas reservoirs

2019 ◽  
Vol 176 ◽  
pp. 456-465 ◽  
Author(s):  
Hewei Tang ◽  
Zhuang Sun ◽  
Youwei He ◽  
Zhi Chai ◽  
A. Rashid Hasan ◽  
...  
Keyword(s):  
Horizontal Wells ◽  
Production Performance ◽  
Gas Reservoirs ◽  
Unconventional Gas ◽  
Unconventional Gas Reservoirs ◽  
Pressure Characteristics

scholarly journals Optimization of Multiple Hydraulically Fractured Horizontal Wells in Unconventional Gas Reservoirs

2013 ◽  
Vol 2013 ◽  
pp. 1-16 ◽  
Author(s):  
Wei Yu ◽  
Kamy Sepehrnoori
Keyword(s):  
Horizontal Wells ◽  
Barnett Shale ◽  
Hydraulic Fractures ◽  
Uncertain Parameters ◽  
Gas Reservoirs ◽  
Well Placement ◽  
Unconventional Gas ◽  
Fracture Conductivity ◽  
Gas Desorption ◽  
Unconventional Gas Reservoirs

Accurate placement of multiple horizontal wells drilled from the same well pad plays a critical role in the successful economical production from unconventional gas reservoirs. However, there are high cost and uncertainty due to many inestimable and uncertain parameters such as reservoir permeability, porosity, fracture spacing, fracture half-length, fracture conductivity, gas desorption, and well spacing. In this paper, we employ response surface methodology to optimize multiple horizontal well placement to maximize Net Present Value (NPV) with numerically modeling multistage hydraulic fractures in combination with economic analysis. This paper demonstrates the accuracy of numerical modeling of multistage hydraulic fractures for actual Barnett Shale production data by considering the gas desorption effect. Six uncertain parameters, such as permeability, porosity, fracture spacing, fracture half-length, fracture conductivity, and distance between two neighboring wells with a reasonable range based on Barnett Shale information, are used to fit a response surface of NPV as the objective function and to finally identify the optimum design under conditions of different gas prices based on NPV maximization. This integrated approach can contribute to obtaining the optimal drainage area around the wells by optimizing well placement and hydraulic fracturing treatment design and provide insight into hydraulic fracture interference between single well and neighboring wells.

Simulated Annealing Algorithm-Based Inversion Model To Interpret Flow Rate Profiles and Fracture Parameters for Horizontal Wells in Unconventional Gas Reservoirs

SPE Journal ◽  
2021 ◽  
pp. 1-21
Author(s):  
Hongwen Luo ◽  
Ying Li ◽  
Haitao Li ◽  
Xiaojiang Cui ◽  
Zhangxin Chen
Keyword(s):  
Simulated Annealing ◽  
Temperature Profile ◽  
Flow Rate ◽  
Horizontal Wells ◽  
Gas Reservoirs ◽  
Unconventional Gas ◽  
Inversion Model ◽  
Fracture Parameters ◽  
Unconventional Gas Reservoirs ◽  
Half Length

Summary With the increasing application of distributed temperature sensing (DTS) in downhole monitoring for multifractured horizontal wells (MFHWs), well performance interpretation by inversing DTS data has become a popular topic around the world. However, because of the lack of efficient inversion models, great challenges still exist in interpreting flow rate profiles and fracture parameters for MFHWs in unconventional gas reservoirs from DTS data. In this paper, a robust inversion system is developed to interpret flow rate profiles and fracture parameters for MFHWs in unconventional gas reservoirs by inversion of DTS data. A temperature prediction model serves as a forward model to simulate the temperature behaviors of MFHWs. A new inversion model based on a simulated annealing (SA) algorithm is proposed to find inversion solutions to flow rate profiles and fracture parameters. The simulated results of temperature behaviors indicate that the temperature profile of each MFHW is irregularly serrated, and the temperature drop in each serration is positively correlated with the inflow rate and fracture half-length. These results provide an excellent method to identify and locate effective hydraulic fractures for field MFHWs. Because of the far more significant influence of fracture half-length than conductivity on a temperature profile, fracture half-length was chosen as the inversion target parameter when performing the inversion of DTS data for MFHWs. Then a synthetic inversion task was accomplished using the SA algorithm-based inversion system, and it took only 110 iterations to reach the target inversion accuracy (10−6 level). Real-time inversion error distributions indicate that this novel inversion system shows great advantages in computational efficiency. Finally, a field application in a shale gas reservoir is presented to validate the reliability of the new inversion model. Based on accurate identification of effective fractures from DTS profiles, satisfactory inversion solutions (the maximum temperature deviation of less than 0.03 K) are obtained. The absolute error of the inversed gas production rate is less than 4 m3/d. The SA algorithm-based inversion system proves reliable to interpret flow rate profiles and fracture parameters, which is a great help to postfracturing evaluation and productivity improvement for MFHWs in unconventional gas reservoirs.

High-Resolution Numerical Modeling of Complex and Irregular Fracture Patterns in Shale-Gas Reservoirs and Tight Gas Reservoirs

2013 ◽  
Vol 16 (04) ◽  
pp. 443-455 ◽  
Author(s):  
O.M.. M. Olorode ◽  
C.M.. M. Freeman ◽  
G.J.. J. Moridis ◽  
T.A.. A. Blasingame
Keyword(s):  
Shale Gas ◽  
Flow Behavior ◽  
Production Performance ◽  
Tight Gas ◽  
Gas Reservoirs ◽  
Unconventional Gas ◽  
Fracture Patterns ◽  
Wide Range ◽  
Unconventional Gas Reservoirs ◽  
Secondary Fractures

Summary Various models featuring horizontal wells with multiple fractures have been proposed to characterize flow behavior over time in tight gas systems and shale-gas systems. Currently, little is known about the effects of nonideal fracture patterns and coupled primary-/secondary-fracture interactions on reservoir performance in unconventional gas reservoirs. We developed a 3D Voronoi mesh-generation application that provides the flexibility to accurately represent various complex and irregular fracture patterns. We also developed a numerical simulator of gas flow through tight porous media, and used several Voronoi grids to assess the potential performance of such irregular fractures on gas production from unconventional gas reservoirs. Our simulations involved up to a half-million cells, and we considered production periods that are orders of magnitude longer than the expected productive life of wells and reservoirs. Our aim was to describe a wide range of flow regimes that can be observed in irregular fracture patterns, and to fully assess even nuances in flow behavior. We investigated coupled primary/secondary fractures, with multiple/vertical hydraulic fractures intersecting horizontal secondary "stress-release" fractures. We studied irregular fracture patterns to show the effect of fracture angularity and nonplanar fracture configurations on production. The results indicate that the presence of high-conductivity secondary fractures results in the highest increase in production, whereas, contrary to expectations, strictly planar and orthogonal fractures yield better production performance than nonplanar and nonorthogonal fractures with equivalent propped-fracture lengths.

Sign in / Sign up

Export Citation Format

Share Document