Modeling Gas Hydrates Using Petroleum Systems Modeling

Björn Wygrala and Wolf Rottke
IES GmbH, Aachen, Germany

Petroleum Systems Modeling is used to simulate temperatures, pressures and hydrocarbon maturation and migration through geologic time. It also enables conditions for gas hydrates to be determined and quantified within the framework of a dynamic geological model. A joint venture between IES, a leading developer of petroleum systems modeling technology, and IFM-GEOMAR, the leading center for marine research in Germany, is therefore being launched to address the modeling of gas hydrates within petroleum systems models. The goal of this project is to enhance the software technology so that the evolution of gas hydrates can be understood and predicted on a quality level similar to modeling oil and gas generation and migration in petroleum systems. There are many similarities between modeling petroleum systems for thermogenic oil and gas, and the modeling of gas hydrates, e.g. the migration of gas into reservoirs which have the required stability conditions.

Modeling the conditions for gas hydrates is based on detailed knowledge of the sedimentological and physical environment of potential reservoirs. A very important parameter is the gas hydrate stability zone (GHSZ). It is defined by special PVT conditions and characterizes an area in which methane can be entrapped as hydrates.

Additionally, the formation of submarine gas hydrates is strongly effected by the flux of methane. Increasing spatial and chronological resolution of the software will enable the petroleum systems modeling to track the generation of methane and its migration into the GHSZ on a very detailed level. The residence time of gas hydrates within the GHSZ and the degradation of gas hydrates can then also be determined.

Expanding the capabilities of the petroleum systems modeling technology in order to improve the qualification of gas hydrates has started with the support of IFM-GEOMAR. The joint development efforts have fundamental long-term benefits, as they will enable new research and development results on gas hydrates to be included in a unique type of dynamic geologic model which will enable the geologic processes and controlling factors to be determined in an increasingly quantitative manner.

Presentation GEO India Expo XXI, Noida, New Delhi, India 2008©AAPG Search and Discovery