An Improved Methodology for Gridding Fractured Reservoirs for Simulation

2021 ◽  
Author(s):  
Sheldon Gorell ◽  
Jim Browning ◽  
Justin Andrews
Keyword(s):  
Reservoir Simulation ◽  
Unstructured Grids ◽  
Fractured Reservoirs ◽  
Simulation Models ◽  
Horizontal Wells ◽  
Design Parameters ◽  
Structured Grids ◽  
Fractured Horizontal Wells ◽  
The Impact ◽  
Base Grid

Abstract A significant amount of research for gridding of complex reservoirs, including models with fractures, has focused on use of unstructured grids. While models with unstructured grids can be extremely flexible, they can also be expensive, both in configuring, computationally, and visual display. Even with this focus on unstructured grids, most reservoir simulation models are still built on structured grids. Current methods for creating reservoir simulation models with structured grids often involve defining a base grid upfront and then "somehow" inserting one or more Features of Interest (FOI's) into the model. Applied to fractured horizontal wells with many stages it can be extremely difficult to accurately align wells and completions within a pre-existing simulation grid. This work describes and demonstrates a methodology to resolve such issues. This approach changes the order of model design and creation steps. This paper describes the process where FOI's are identified, a base grid is designed around the FOI's, then local grid refinements (LGR's) are defined as desired. Applied to a horizontal well with fractures, the well and completion locations are defined before the detailed grid definition is created. This process is illustrated for generalized FOI's, and then applied to fractured horizontal wells. Formulas for creation of models for wells with evenly space homogeneous completions are presented. Numerical testing and analyses are presented that show the impact of the gridding parameters and various design parameters on performance of reservoir simulations.

scholarly journals Simulação de Reservatórios de Óleo Leve com Poço Horizontal Hidraulicamente Fraturado

2017 ◽  
Vol 2 (2) ◽  
Author(s):  
Helio Souto
Keyword(s):  
Hydraulic Fracturing ◽  
Reservoir Simulation ◽  
Horizontal Well ◽  
Fractured Reservoirs ◽  
Horizontal Wells ◽  
Preconditioned Conjugate Gradient ◽  
Hydraulic Fractures ◽  
Tight Oil ◽  
Wellbore Pressure ◽  
Fractured Horizontal Wells

<p>Since the 1960s, because of the relevance to the oil industry, the numerical simulation of hydrocarbon reservoirs has received special attention and has been the subject of extensive studies. The main goal of computational modeling and the use of numerical methods for reservoir simulation is to allow better placement and control of wells, so that there is a optimized oil recovery. In this work, production of hydraulically fractured horizontal wells in light tight oil reservoirs will be studied. In this case, fractures do not form a continuous conductive network and can communicate hydraulically with only the horizontal producer well. In order to do that, a simulator for three-dimensional oil flow in reservoirs, suitable for applications in the field scale, already developed, using the Cartesian coordinate system and a finite difference approach, will be applied for the study of hydraulically fractured horizontal wells. Originally, this simulator and its grid refinement tools had been used only on the simulation of naturally fractured reservoirs. The nonlinear partial differential equation resulting from physical-mathematical modeling, written in terms of pressure, will be solved numerically after discretization and linearization using the Preconditioned Conjugate Gradient method. The main objective is to study the combined effects of hydraulic fractures and horizontal well on the wellbore pressure profile, considering different light tight oil production scenarios. Numerical simulations displayed the influence of important parameters on the well-reservoir system in study, such as fracture permeability and matrix porosity. A study of this type is relevant on the discussion of reservoir production strategies, helping on the decisions about a hydraulic fracturing operation in order to obtain economic viability for the hydrocarbons recovery project.</p><p><strong>Keywords</strong>: reservoir simulation, light tight oil, horizontal well, hydraulic fracturing, nite diferences method.</p>

Grid-Sensitivity Analysis and Comparison Between Unstructured Perpendicular Bisector and Structured Tartan/Local-Grid-Refinement Grids for Hydraulically Fractured Horizontal Wells in Eagle Ford Formation With Complicated Natural Fractures

SPE Journal ◽  
2016 ◽  
Vol 21 (06) ◽  
pp. 2260-2275 ◽  
Author(s):  
Jianlei Sun ◽  
David Schechter ◽  
Chung-Kan Huang
Keyword(s):  
Horizontal Wells ◽  
Work Flow ◽  
Hydraulic Fractures ◽  
Grid Refinement ◽  
Fracture Networks ◽  
Structured Grids ◽  
Local Grid Refinement ◽  
Production Behavior ◽  
Local Grid ◽  
Fractured Horizontal Wells

Summary In the context of modeling fractured horizontal wells, unstructured grids have been applied to generate simulation meshes for complex fracture networks. It is necessary to investigate how to choose an unstructured mesh to accurately simulate production performance. In this paper, a new unstructured gridding and discretization work flow is proposed to handle nonorthogonal and low-angle intersections of extensively clustered fractures with nonuniform apertures. The work flow is then validated with two models in terms of production behavior and central-processing-unit (CPU) performance: a synthetic model with one horizontal well and orthogonal intersected hydraulic fractures built by tartan grid, and a field-scale local-grid-refinement (LGR) model with three horizontal wells and irregular hydraulic fractures in a slightly dipping reservoir created by a commercial software plug-in. Good-quality matches are obtained between unstructured and structured grids in both pressure and production behavior. Sensitivity analysis of the meshing parameters suggests that refinement in the vicinity of fractures has improved both early and late production of a well, whereas background density has a dominant effect on the late production. Background-grid type and orientation have less influence as long as they have the same grid density. Fewer cells can be achieved by increasing reservoir-background size and size-progression ratio, replacing unstructured-background grids with structured grids, and reducing the complexity of the fracture networks without loss of the accuracy, resulting in improved CPU performance. This study applies unstructured grids to simulate multiple horizontal wells with complicated fracture networks, and provides detailed comparisons between unstructured and structured grids. Most importantly, it resolves the question regarding how to choose an appropriate mesh to yield both accurate results and high-quality CPU performance.

Improving Oil Recovery Through Fracture Injection and Production of Multiple Fractured Horizontal Wells

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Youwei He ◽  
Shiqing Cheng ◽  
Zhe Sun ◽  
Zhi Chai ◽  
Zhenhua Rui
Keyword(s):  
Oil Recovery ◽  
Oil Production ◽  
Horizontal Wells ◽  
Co2 Injection ◽  
Production Rates ◽  
Well Production ◽  
Well Completion ◽  
Tight Formations ◽  
Fractured Horizontal Wells ◽  
The Impact

Abstract Well production rates decline quickly in the tight reservoirs, and enhanced oil recovery (EOR) is needed to increase productivity. Conventional flooding from adjacent wells is inefficient in the tight formations, and Huff-n-Puff also fails to achieve the expected productivity. This paper investigates the feasibility of the inter-fracture injection and production (IFIP) method to increase oil production rates of horizontal wells. Three multi-fractured horizontal wells (MFHWs) are included in a cluster well. The fractures with even and odd indexes are assigned to be injection fractures (IFs) and recovery fractures (RFs). The injection/production schedule includes synchronous inter-fracture injection and production (s-IFIP) and asynchronous inter-fracture injection and production (a-IFIP). The production performances of three MFHWs are compared by using four different recovery approaches based on numerical simulation. Although the number of RFs is reduced by about 50% for s-IFIP and a-IFIP, they achieve much higher oil rates than depletion and CO2 Huff-n-Puff. The sensitivity analysis is performed to investigate the impact of parameters on IFIP. The spacing between IFs and RFs, CO2 injection rates, and connectivity of fracture networks affect oil production significantly, followed by the length of RFs, well spacing among MFHWs, and the length of IFs. The suggested well completion scheme for the IFIP methods is presented. This work discusses the ability of the IFIP method in enhancing the oil production of MFHWs.

scholarly journals Analysis of the influence of design parameters on the agro-ecological qualities of tractor tires

2021 ◽  
Vol 937 (3) ◽  
pp. 032010
Author(s):  
V Kravchenko ◽  
L Kravchenko ◽  
V Oberemok ◽  
A Avanesyan
Keyword(s):  
Experimental Studies ◽  
Simulation Models ◽  
Contact Spot ◽  
Design Parameters ◽  
Physical Processes ◽  
Software Environment ◽  
Ground System ◽  
Mobile Machinery ◽  
The Impact ◽  
Normal Deflection

Abstract Experimental studies of the impact of agricultural mobile machinery movers on the soil are seasonal in nature and require complex experimental equipment. The complexity of the physical processes occurring in the elastic wheel-ground system requires the introduction of many assumptions and limitations that reduce the accuracy of the results, according to the design of simulation models performed in the software environment. The aim of the research was to study the influence of the design parameters of the tire on the efficiency of the normal deflection along the contact spot zone X. Studies have shown that 65% to 77% of the normal deflection of the tire is used when passing the contact spot. The reinforcement parameters of the tire frame have the greatest impact on the efficiency of the normal deflection along the contact spot zone. With an increase in the number of layers of the frame cord from 2 to 8, the coefficient of usability of the normal deviation for the stroke of the contact spot decreases from 0.761 to 0.689, with an increase in the angle of inclination of the frame cords - decreases from 0.755 to 0.693.

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