Code comparison of methane hydrate reservoir simulators using CMG STARS

• Main Author: Gaddipati, Manohar
• Format: Text
• Language: unknown
• Published: The Research Repository @ WVU 2008
• Subjects: Chemical engineering; Petroleum engineering; Methane hydrate; Prudhoe Bay
• Online Access: https://researchrepository.wvu.edu/etd/1973; https://researchrepository.wvu.edu/cgi/viewcontent.cgi?article=2977&context=etd

Natural gas is an important energy source contributing to 23% of the total energy consumption in United States. Domestic conventional natural gas production does not keep pace with increase in natural gas demand. Development of new alternatives like natural gas from methane hydrate can play a major role in ensuring adequate future energy supplies in the United States.;Methane hydrates are crystalline solids, very similar to ice, in which non-polar molecules are trapped inside the cages of water molecules. Methane hydrates could be potentially a vast source of energy. It is estimated that the total amount of natural gas trapped inside the hydrate is approximately two times the total unconventional oil-gas reserves in the world. The production of natural gas from hydrates economically poses a big challenge to today's scientific world. Over the years, different reservoir simulators were developed and different approaches have been used to model the gas hydrate dissociation behavior. The National Energy Technology Laboratory (NETL) and the U.S Geological Survey (USGS) gas hydrate code comparison project is the first of its kind and it aims at a worldwide understanding of the hypotheses involved in the gas hydrate modeling and problem solving. This code comparison study is conducted to compare various hydrate reservoir simulators like CMG STARS, TOUGH-Fx/Hydrate, MH21, STOMP, HydrateResSim and a code form University of Houston.;The objective of this Project is to generate results for different problems set by the code comparison participants using CMG STARS and to validate its results with other reservoir simulators. Results obtained are in good agreement with other simulators in the study. However minor differences were observed for a problem with ice in the system. Long term simulations were conducted for Mt Elbert, Prudhoe Bay L-PAD like deposits. The Production rates obtained using CMG STARS were in good agreement with other packages.;In addition to the code comparison problems, simulations to analyze the sensitivity to various parameters were performed. Studies were carried out with heterogeneity introduced in the reservoir properties using the Mt. Elbert stratigraphic test well data and results showed that higher production was observed with the incorporation of heterogeneity. Sensitivity analysis of seven reservoir parameters was done using Plackett-Burman design to gain a better understanding on production performance. The reservoir parameters were ranked based on effects of the reservoir parameters on production rates.