Goals and Research Themes for Research Group for Production Method and Modeling

Goals

For commercial production of methane gas from methane hydrate-bearing layers, a production method with stable and massive production of methane gas from methane hydrate-bearing layers, evaluation technology for predicting and analyzing with a high precision the production behaviors of the target methane hydrate resource field and the gas production capacities of wells, and evaluation technology of sedimentary characterization for ensuring long-term safety of sedimentary deformation and consolidation behavior as following production, are required to be developed. From such significance, the research and development activity concerning development of the production method including the following R&D objectives, will be conducted to establish an economical and efficient production method.

  • Development of technology for advanced production method
  • Development of evaluation technology for productivity and production behaviors
  • Development of evaluation technology for sediment characteristics

Contents of the research and development

  • Development of technology for advanced production method

The higher the initial reservoir temperature, the higher rates of methane gas production and recovery are expected when the depressurization method is applied to a methane hydrate-bearing layer with alternation of sand and mud. However, the production rate gradually decreases due to reduction of the reservoir temperature during the production process. Therefore, the research includes development of a composite production method (combined method) for recovering the reservoir temperature. Also, the other production methods including a sediment-thermal stimulation method for economic and efficient heat supply, an accelerated recovery method focused on the reservoir characteristics providing high permeability layers after production, a method for improving the permeability factor that contributes to initial productivity, and so on, will be developed. Furthermore, in order to ensure long-term stable methane gas production, MH21 will conduct quantitative analyses of productivity impediments through the development of numerical models, which includes production-impeding impact of sand production, reductions of permeability due to skin formation, flow obstruction due to methane hydrate reproduction, and so on, and develop technologies to counter and control the production damages.

Major activities

  • Development of technology to enhance productivity
  • Development of technology to counter/control production damages.
  • Verification with large-scale laboratory test equipment
  • Development of evaluation technology for productivity and production behaviors

MH21 will develop a technology for providing more reliable productivity and predicting production behaviors by adding the models such as variations of reservoir characteristics owing to the production process and so on into the production simulator developed in Phase 1 (MH21-HYDRES). For that purpose, MH21 will work on upgrading the production simulator, , by developing an analysis routine for evaluating changes following production in relation to permeability of the reservoir, thermal characteristics, consolidation properties, etc., and for evaluating production damages through verification of onshore gas hydrate production tests and offshore production tests. As for the three-dimensional reservoir models to be loaded into the production simulator, MH21 will aim to evaluate production behaviors in wider-area, sediment characteristics, etc., in long-term production by considering introduction of discontinuity such as faults, heterogeneous reservoir parameters, and so on. Based on these results, MH21 will conduct a comprehensive evaluation of the production method and system for optimizing economic potential according to the reservoir characteristics.

Major activities

  • Functional improvement of production simulator (MH21-HYDRES)
  • Development of three-dimensional reservoir model for production behavior evaluation
  • Prediction and verification of production tests
  • Productivity evaluation of commercial-scale production
  • Development of evaluation technology for sediment characteristics

Through advancing sets of formulas in the sediment deformation simulator developed in Phase 1, an evaluation routine will be developed, which enables assessment of environmental impact such as probability of landslide, a risk of methane gas leakage, and so on that may follow methane gas production. Also, by using the above routine, MH21 will comprehensively evaluate mechanical properties peculiar to methane hydrate development of deep-water unconsolidated sedimentary layers and verify the geo-mechanical stress around wells relating to the methane gas production, boarder-area sediment deformation accompanying long-term production, and so on.

Major activities

  • Functional improvement of sediment deformation simulator
  • Evaluation of well integrity
  • Evaluation of sediment deformation in boarder area

Goals of Phase 2

Goal (FY 2011) Goal (FY 2015)
Research and Development concerning Production Method Development
1. Development of technology for advanced production method
Development of technology for enhancing gas productivity
Develop the technologies for enhancing gas productivity per well through the methane hydrate sedimentary core testing, by combing depressurization method and thermal stimulation methods, by increasing the methane gas production rate with effective thermal supply, by improving the permeability, etc. Develop the production method adjusting to the reservoir characteristics in order to maximize the gas production rate per well.
Development of technology to counter/control production impediments
Through the methane hydrate sedimentary core testing , clarify the mechanism of gas production impediments and assess its impact on gas production by analyzing the production impediments such as skin formation around the production well, accumulation of moving fine-grained sands into the pore of sandy sediment, ice formation/methane hydrate regeneration at a strong depressurization, production impediment such as lowering of permeability due to consolidation, and the flow obstruction due to regeneration of methane hydrate in the tubing. Develop technology for controlling production impediments such as sanding, skin, accumulation of fine-grained sands, methane hydrate/ice formation, flow obstruction, etc. and develop a guideline for the countermeasures coping to production impediments suitable for the target reservoir characteristics.
Verification with large-scale laboratory test equipment
Design and construct a large-scale laboratory test equipment to quantitatively evaluate the gas productivity and production behavior, and verify the technology to enhance the gas productivity and the production impediment mechanism. Verify the technology to enhance gas productivity and control production impediments, and present an effective production method through overall evaluation of the developed technology, verification with offshore production test, and so on.
Goal (FY 2011) Goal (FY 2015)
2. Development of evaluation technology for productivity and production behaviors
Functional improvement of production simulator (MH21-HYDRES)
Enhance the function of the production simulator (MH21-HYDRES) by adding a routine which is able to evaluate various production impediment factors such as flow obstruction due to skin formation. Also, accelerate the processing speed of the simulator by developing the parallel computing method and implementing it into the system. Also, develop the upscale method which ensures efficient simulation while maintaining accuracy to estimate the productivity and production behavior at the field. Improve the accuracy through verification of the result of the field test. Also develop a practical simulator that combines the production simulator with the sediment deformation simulator.
Development of three-dimensional reservoir model for production behavior evaluation
Obtain the sedimentary parameters which can describe sediment heterogeneity and discontinuity due to fault through experiments, etc. Develop a modeling procedure for the three-dimensional reservoir models which enables to evaluate the long-term gas productivity and sediment deformation. By introducing the sediment stochastic method, develop a modeling procedure for the three-dimensional reservoir models which is able to evaluate the gas production behavior and sediment deformation in wide area during the long-term production period.
Prediction and verification of production test
Predict the gas productivity and production behavior of onshore gas hydrate production tests and offshore production tests, and incorporate the prediction to the test plans. Also, verify the reliability of the production simulator with the result of the production tests. Predict the gas productivity and production behavior of offshore production tests, and incorporate the prediction to the test plans. Also, verify the reliability of the production simulator with the result of the production tests.
Productivity evaluation of commercial-scale production
Evaluate the long-term gas productivity of several production systems developed as adjusting to the reservoir characteristics, and present an economically feasible production system. Evaluate the rational production system, develop a guideline for the production system design which ensures economical feasibility, and perform an LCA evaluation by using the simulator.
Goal (FY 2011) Goal (FY 2015)
3. Development of evaluation technology for sediment characteristics
Functional improvement of sediment deformation simulator
Develop the sediment deformation simulator for analyzing broader area of sediment stress distribution, deformation behavior and consolidation behavior in the methane hydrate-bearing reservoir consisting of alternation of sand and mud. Also, develop the analytical simulator for geomechanical behavior which enables to evaluate the detailed dynamic behavior around the well and evaluate the long-term stability of the well. Develop the sediment deformation simulator for the reservoir model including the discontinuity and heterogeneity which enables to evaluate stress distribution and deformation of the sediment, subsidence behavior of the seafloor , possibilities of landslide, and gas leakage both around the well and broader area during the production.
Evaluation of well integrity
According to the reservoir characteristics, evaluate the sediment deformation around the well, stress distribution of sediment on the wellbore wall, and possibility of gas leakage during the gas production process. In order to ensure the well integrity during the gas production, present a guideline of the strength of the well, cement strength, well completion method, etc.
Evaluation of sediment deformation in broader area
Examine the subsidence of seafloor, deformation of sediment, possibilities of landslide, and gas leakage in broader area during the gas production. Also, summarize the geomechanical characteristics of deep-water shallow formation unconsolidated sedimentary layers. Develop the technology to evaluate risks on the sedimentary layer for a long-term and broader-area gas production, and develop a guideline for selecting the development area to avoid such risks.

コメントは停止中です。