1.Introduction
The petroleum & natural gas engineering lab was founded in order to foster petroleum engineers in the oil and gas industries. The lab carries out experimental and numerical analyses, from which results are expected to be used in field development or production forecast. We have been focused on unconventional oil & gas resources which are 'hot areas' in the world as the natural resources. Especially, the lab implements developing evaluation methodologies and techniques for field monitoring, well control and production optimization. The research topics are mainly based on analysis of unconventional resources, such as shale gas, coalbed methane (CBM) and gas hydrate as well as in the field of enhanced oil recovery.
2. Research Area
○ Shale Gas
① Low permeability measurement apparatus (LPMA)
Permeability and porosity are critical parameters of the oil and gas reservoirs that determine their viability for commercial development. Permeability of the reservoir rock samples is often measured using a constant flow equipment. However, in case of shale gas reservoir as permeability is lower than 0.001 md. Thus, the experiments spend a lot of time and show inaccurate results.
We developed a new apparatus which can simultaneously measure low permeability and porosity to reduce total testing time, and measure bidirectional permeability efficiently. Using the apparatus, we analyzed the physical properties of shale and tight rock and carried out correlation analysis of parameters affecting rock properties.
② Adsorptive low permeability matrix analyzer (ALPMA)
Shale gas reservoirs have nanopores, which contribute gas diffusion in the shale matrix. Unlike the conventional resources, natural gas stored in shale gas reservoir is believed to exist as not only free gas in pores and fractures but also adsorbed gas on organic matter. Thus, it needs to investigate the adsorption and diffusion characteristics of shale gas reservoirs.
We developed an experimental apparatus to measure the shale porosity and permeability at nanoscale. The apparatus can also measure the adsorption capacity of shale. The measured properties were used to analyze the gas diffusion at nanoscale and adsorption characteristics.
○ Enhanced Oil Recovery (EOR)
EOR is the most realistic way to solve rapidly increasing demand and declining supply of oil. In particular, polymer flooding is used to increase viscosity of the injection water and thereby improve mobility ratio for displacing oil in a reservoir and highly estimated as a stabilized EOR technique.
For evaluating the efficiency of polymer flooding, we analyze the performance characteristics in contact region of injection fluid and establish the method of frontal advance analysis considering rheology characteristics. We are also carrying out a study of real-time injection performance for polymer flooding in heterogeneous reservoirs.
○ Coalbed Methane (CBM) ① Pressure transient analysis
CBM is one of the representative areas of unconventional gas. It allows easier access for a non-oil country because, unlike conventional gas or oil reserves, CBM is not concentrated in specific major areas. The most critical factor in developing CBM reservoirs is absolute permeability. In case of CBM, permeability should be obtained from well test because it is difficult to obtain permeability from core analysis.
Our work is pressure transient analysis of CBM reservoirs. We designed the appropriate well test depending on properties of reservoirs and established an interpretation system using two commercial software. The interpretation system will be used for evaluation economics of a reservoir and figuring out productivity.
② Technical screening guide system
The structural complexity of a coalbed may affect CBM project economics. To select optimal engineering applications to maximize the well performance, it is important to consider the influence of these geological parameters on the success of specific drilling, completion, or stimulation methods. However, instead of geological parameters, empirical methods are being used in most CBM fields, which might not be reasonable for selecting a feasible method.
We developed a technical screening guide system to assist the selection of production methods such as drilling, completion, and stimulation in a CBM reservoir. The system was developed using an artificial neural network (ANN). In order to develop the system, a field database was constructed and the system to select drilling and completion method, and hydraulic fracturing fluid was developed by utilizing the database. Then, a graphical user interface was developed in order to make access to the developed systems user-friendly. The systems were integrated into a single application, and an effective system was created for selecting appropriate CBM production methods.
○ Carbon Dioxide Sequestration
Society has made efforts to protect the earth from greenhouse gases, which have caused global warming and climate change leading to flood damage and sweltering heat. For this reason, carbon capture and storage (CCS) Technology, which could reduce carbon dioxide emission, has risen as a realistic alternative in recent years. Most of the large existing CO2 point sources are within easy access of saline formation injection points. Therefore, sequestration in a saline formation is compatible with a strategy of migrating large portions of existing energy and industrial assets to near zero carbon emission via low cost carbon sequestration retrofits.
We developed an evaluation model on feasibility of CO2 sequestration in saline aquifer using an ANN. To develop the evaluation model, a sensitivity analysis were conducted to find out the most important parameters that affect the CO2 sequestration mechanism in deep saline aquifer using a commercial simulator and the factors and ranges influencing CO2 sequestration were decided. Using the factors and ranges, ANN predictive model was developed to evaluate residual and solubility CO2 trapping mechanisms.
3. Research Projects (2011~Present)
○ A Technique Development for the Production Estimation of Shale and Tight Gas Fields
○ Development of Enhanced Oil Recovery Technology using Novel Polymer Flooding
○ Research on the Commercialization of Project Valuation and Applicable Standards for CBM Development Technology
○ A Study on the Well Test Design and Interpretation for Coalbed Methane
○ Development of an Evaluation Model on the Feasibility of CO2 Sequestration Using Artificial Neural Networks
○ Study on the Classification of Technical Characteristics and Fusion and Complex R&D Plan for the Arctic Oil and Gas Resources
○ A Study on the Strategy of Technical Development for Arctic Oil and Gas Resources
4. Contact
3A-214 Department of Energy & Resources Engineering, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju, Korea
Phone : +82-62-530-0248
URL : http://petro.jnu.ac.kr/