Operation Overview of the 2002 Mallik Gas Hydrate Production Research Well Program at the Mackenzie Delta in the Canadian Arctic

Abstract

Abstract The first production test of methane hydrate layers was carried out at the Mackenzie Delta in the Canadian Arctic. Three wells, named JAPEX/JNOC/GSC et al. Mallik 3L-38, 4L-38 and 5L-38, were drilled through hydrate layers at depths of approximately 900-1100m beneath 640m of permafrost on a line at 40m spacing. Coring, logging, various scientific experiments and production testing were performed over a 79- day period from December 2001 to March 2002. This research project was funded by participants from Japan, Canada, US, Germany and India. The Geological Survey of Canada (GSC) was the coordinator of the science program and Japan National Oil Corporation (JNOC) along with Japan Petroleum Exploration Co. (JAPEX) were the operators. JAPEX Canada Ltd., a subsidiary of JAPEX, acted as the legal operator in Canada and Canadian Petroleum Engineering Inc. (CPE) was retained to provide JAPEX with operational management for the remote arctic environment. The production testing was achieved using two testing methods. Six short duration depressurization tests were conducted using Schlumberger's Modular Dynamic Formation Tester (MDT). A longer duration, thermal stimulation test was carried out by circulating hot fluid past the hydrate layers. An extensive research program was conducted to monitor the formation response to the testing. Cross well tomography surveys were conducted from the observation wells before and during the testing. The post-test wireline log response was compared with pre-test log. The wellbore temperatures were monitored on all wells using fiber-optic cables. These data are valuable for improving the reservoir simulation models to assess gas hydrate production. A practical model is essential for a country such as Japan that has been seeking to economically develop deep water marine gas hydrates off its coast. This paper describes the field operation, explaining how all the programs were accomplished successfully in the limited operational period. The full research gas hydrate research program being conducted at the Mallik site is ongoing with a scheduled public release of the results expected on or before August 2004. Background Gas hydrate accumulations within deepwater marine sediments and below Arctic permafrost are being considered by a number of countries as a possible energy source for future. Japan, which has little conventional hydrocarbon reserves and surrounded by deepwater, has been seeking to develop the potential of gas hydrates in the last decade. In the past five years, JNOC has operated three field experiments in collaboration with JAPEX to assess commercial and scientific goals, under promotion of METI (Ministry of Economy, Trade and Industry). The first field experiment was executed in February to March 1998 at the Mackenzie Delta in the Canadian Arctic as collaboration between JNOC and GSC with the participation of USGS (US Geological Survey) and JAPEX. At that time a well named JAPEX/JNOC/GSC Mallik 2L-38 was drilled/cored/logged through the hydrate layers beneath permafrost1. This research program was carried out to better understand gas hydrate characteristics and to verify the technologies required to evaluate its occurrence in the sediments2.