Impact of Well Placement in the Fractured Geothermal Reservoirs Based on Available Discrete Fractured System

Well placement optimization in a given geological setting for a fractured geothermal reservoir is a prerequisite for enhanced geothermal operations. High computational cost associated in the framework of fully coupled thermo-hydraulic-mechanical (THM) processes in a fractured reservoir simulation, makes the well positioning as a missing point in developing a field scale investigation. Here, in this study, we shed light on this topic through examining different injection-production well (doublet) position in a given real fracture network. Water and CO2 are used as working fluids for geothermal operations and importance of well positions are examined using coupled THM numerical simulations for both the fluids. Results of this study are examined through the thermal breakthrough time, mass flux and the energy extraction potential to assess the impact of well position in a two-dimensional reservoir framework. Almost ten times of the difference between the final amount of heat extraction is observed for different well position but with the same well spacing and geological characteristics. Furthermore, stress field is be a strong function of well position that is important with respect to the possibility of unwanted stress development. As part of the MEET project, this study recommends to perform similar well placement optimization study for each fracture set in a fully coupled THM manner before a field well drilling.

Download Full-text

Impact of Well Placement in the Fractured Geothermal Reservoirs Based on Available Discrete Fractured System

Geosciences ◽

10.3390/geosciences12010019 ◽

2022 ◽

Vol 12 (1) ◽

pp. 19

Author(s):

Saeed Mahmoodpour ◽

Mrityunjay Singh ◽

Kristian Bär ◽

Ingo Sass

Keyword(s):

High Stress ◽

Computational Cost ◽

Fracture Network ◽

Heat Extraction ◽

Fractured Reservoir ◽

Computationally Efficient ◽

Production Well ◽

Well Placement ◽

Working Fluids ◽

The Impact

Well placement in a given geological setting for a fractured geothermal reservoir is necessary for enhanced geothermal operations. High computational cost associated with the framework of fully coupled thermo-hydraulic-mechanical (THM) processes in a fractured reservoir simulation makes the well positioning a missing point in developing a field-scale investigation. To enhance the knowledge of well placement for different working fluids, we present the importance of this topic by examining different injection-production well (doublet) positions in a given fracture network using coupled THM numerical simulations. Results of this study are examined through the thermal breakthrough time, mass flux, and the energy extraction potential to assess the impact of well position in a two-dimensional reservoir framework. Almost ten times the difference between the final amount of heat extraction is observed for different well positions but with the same well spacing and geological characteristics. Furthermore, the stress field is a strong function of well position that is important concerning the possibility of high-stress development. The objective of this work is to exemplify the importance of fracture connectivity and density near the wellbores, and from the simulated cases, it is sufficient to understand this for both the working fluids. Based on the result, the production well position search in the future will be reduced to the high-density fracture area, and it will make the optimization process according to the THM mechanism computationally efficient and economical.

Download Full-text

Well-Placement Optimization in an Enhanced Geothermal System Based on the Fracture Continuum Method and 0-1 Programming

Energies ◽

10.3390/en12040709 ◽

2019 ◽

Vol 12 (4) ◽

pp. 709 ◽

Cited By ~ 4

Author(s):

Liming Zhang ◽

Zekun Deng ◽

Kai Zhang ◽

Tao Long ◽

Joshua Desbordes ◽

...

Keyword(s):

Numerical Simulation ◽

Optimization Method ◽

Geothermal System ◽

Enhanced Geothermal System ◽

Fractured Reservoir ◽

Well Placement ◽

Well Drilling ◽

Thermal Reservoir ◽

Placement Optimization ◽

Well Placement Optimization

The well-placement of an enhanced geothermal system (EGS) is significant to its performance and economic viability because of the fractures in the thermal reservoir and the expensive cost of well-drilling. In this work, a numerical simulation and genetic algorithm are combined to search for the optimization of the well-placement for an EGS, considering the uneven distribution of fractures. The fracture continuum method is used to simplify the seepage in the fractured reservoir to reduce the computational expense of a numerical simulation. In order to reduce the potential well-placements, the well-placement optimization problem is regarded as a 0-1 programming problem. A 2-D assumptive thermal reservoir model is used to verify the validity of the optimization method. The results indicate that the well-placement optimization proposed in this paper can improve the performance of an EGS.

Download Full-text

A Modified Niching Crow Search Approach to Well Placement Optimization

Energies ◽

10.3390/en14040857 ◽

2021 ◽

Vol 14 (4) ◽

pp. 857

Author(s):

Jahedul Islam ◽

Md Shokor A. Rahaman ◽

Pandian M. Vasant ◽

Berihun Mamo Negash ◽

Ahshanul Hoqe ◽

...

Keyword(s):

Optimization Problem ◽

Search Algorithm ◽

Gravitational Search Algorithm ◽

Multimodal Optimization ◽

Test Functions ◽

Well Placement ◽

Suggested Approach ◽

Placement Optimization ◽

Well Placement Optimization ◽

Search Approach

Well placement optimization is considered a non-convex and highly multimodal optimization problem. In this article, a modified crow search algorithm is proposed to tackle the well placement optimization problem. This article proposes modifications based on local search and niching techniques in the crow search algorithm (CSA). At first, the suggested approach is verified by experimenting with the benchmark functions. For test functions, the results of the proposed approach demonstrated a higher convergence rate and a better solution. Again, the performance of the proposed technique is evaluated with well placement optimization problem and compared with particle swarm optimization (PSO), the Gravitational Search Algorithm (GSA), and the Crow search algorithm (CSA). The outcomes of the study revealed that the niching crow search algorithm is the most efficient and effective compared to the other techniques.

Download Full-text

Infill well placement optimization in two-dimensional heterogeneous reservoirs under waterflooding using upscaling wavelet transform

Journal of Petroleum Science and Engineering ◽

10.1016/j.petrol.2021.108439 ◽

2021 ◽

Vol 201 ◽

pp. 108439

Author(s):

Adel Malallah ◽

Amna Alashwak ◽

Ibrahim Sami Nashawi

Keyword(s):

Wavelet Transform ◽

Two Dimensional ◽

Well Placement ◽

Heterogeneous Reservoirs ◽

Placement Optimization ◽

Well Placement Optimization

Download Full-text

Embedded discrete fracture modeling: Flow diagnostics, non-Darcy flow, and well placement optimization

Journal of Petroleum Science and Engineering ◽

10.1016/j.petrol.2021.109477 ◽

2022 ◽

Vol 208 ◽

pp. 109477

Author(s):

Shuai Ma ◽

Binshan Ju ◽

Lin Zhao ◽

Knut-Andreas Lie ◽

Yintao Dong ◽

...

Keyword(s):

Darcy Flow ◽

Well Placement ◽

Flow Diagnostics ◽

Placement Optimization ◽

Fracture Modeling ◽

Discrete Fracture ◽

Well Placement Optimization ◽

Modeling Flow

Download Full-text

Selection of Representative Scenarios Using Multiple Simulation Outputs for Robust Well Placement Optimization in Greenfields

10.2118/206300-ms ◽

2021 ◽

Author(s):

Seyed Kourosh Mahjour ◽

Antonio Alberto Souza Santos ◽

Susana Margarida da Graca Santos ◽

Denis Jose Schiozer

Keyword(s):

Reference Model ◽

Simulation Models ◽

Cumulative Distribution ◽

Small Subset ◽

Fine Grid ◽

Well Placement ◽

Placement Optimization ◽

Well Placement Optimization ◽

Selection Of ◽

Dynamic Uncertainties

Abstract In greenfield projects, robust well placement optimization under different scenarios of uncertainty technically requires hundreds to thousands of evaluations to be processed by a flow simulator. However, the simulation process for so many evaluations can be computationally expensive. Hence, simulation runs are generally applied over a small subset of scenarios called representative scenarios (RS) approximately showing the statistical features of the full ensemble. In this work, we evaluated two workflows for robust well placement optimization using the selection of (1) representative geostatistical realizations (RGR) under geological uncertainties (Workflow A), and (2) representative (simulation) models (RM) under the combination of geological and reservoir (dynamic) uncertainties (Workflow B). In both workflows, an existing RS selection technique was used by measuring the mismatches between the cumulative distribution of multiple simulation outputs from the subset and the full ensemble. We applied the Iterative Discretized Latin Hypercube (IDLHC) to optimize the well placements using the RS sets selected from each workflow and maximizing the expected monetary value (EMV) as the objective function. We evaluated the workflows in terms of (1) representativeness of the RS in different production strategies, (2) quality of the defined robust strategies, and (3) computational costs. To obtain and validate the results, we employed the synthetic UNISIM-II-D-BO benchmark case with uncertain variables and the reference fine- grid model, UNISIM-II-R, which works as a real case. This work investigated the overall impacts of the robust well placement optimization workflows considering uncertain scenarios and application on the reference model. Additionally, we highlighted and evaluated the importance of geological and dynamic uncertainties in the RS selection for efficient robust well placement optimization.

Download Full-text