Overview of thermal-stimulation production-test results for the JAPEX/JNOC/GSC et al. Mallik 5L-38 gas hydrate production research well

Abstract

Abstract:The thermal-stimulation test conducted on the JAPEX/JNOC/GSC et al. Mallik 5L-38 gas hydrate production research well in March of 2002 was designed to increase the in situ temperature of a portion of a well defined and constrained gas hydrate reservoir above the gas hydrate stability point, while maintaining constant pressure. Data collected, including surface and downhole instrumentation readings and data from advanced logging and seismic programs, were then used to calibrate numerical gas hydrate reservoirsimulation models and determine the kinetic and thermodynamic properties of the in situ gas hydrate.The thermal-stimulation test was successful: bottomhole temperature was increased to greater than 50°C during the test; gas from dissociated gas hydrate was produced, sampled, and flared at surface; and significant amounts of real-time downhole temperature and pressure data, as well as other scientific measurements, were obtained. L'essai de stimulation thermique a été une réussite : on a pu accroître la température au fond du puits à plus de 50°C durant l'essai; on a produit, échantillonné et brûlé à la surface du gaz naturel provenant de la dissociation des hydrates de gaz; et on a généré, entre autres données scientifiques, une quantité considérable de mesures de température et de pression, acquises en temps réel dans le puits.

Analysis and interpretation of the thermal test of gas hydrate dissociation in the JAPEX/JNOC/GSC et al. Mallik 5L-38 gas hydrate production research well

“…The detailed design of the Mallik thermal-production test is discussed in several papers within this publication, including Satoh et al (2005) and Hancock et al (2005). The thermalproduction test was carried out by circulating hot water across a 13 m perforated gas-hydrate-bearing section from 907 to 920 m. Hot water circulating in the well came in contact with the gas hydrate in the gas-hydrate-bearing formation, causing dissociation of the gas hydrate.…”

Thermal conductivity of sediments within the gas-hydrate-bearing interval at the JAPEX/JNOC/GSC et al. Mallik 5L-38 gas hydrate production research well

“…As described by Hancock et al (2005), the test consisted of controlled heating of a 13 m thick perforated zone, extending from 907 to 920 m, using a hot-brine circulating fluid. The methane gas released from the dissociated gas hydrate was separated from the circulating fluid at the surface and measured.…”

A theoretical model for predicting the spatial distribution of gas hydrate dissociation under the combination of depressurization and heating without the discontinuous interface assumption

“…The reported in-situ tests of gas production from GH are carried out in Mackenzie Delta, Alaska North Slope, and Nankai Trough (Takahashi et al, 2003;Hancock et al, 2005;Kurihara et al, 2008;Moridis et al, 2011;ConocoPhillips, 2012;David, 2013). During these in-situ production tests, downhole pressures of the production wells in Mallik, Ignik Sikumi, and Nankai Trough are reduced from 11.2 MPa to 7.3 MPa (Kurihara et al, 2008;Moridis et al, 2011), 8.1-1.8 MPa (ConocoPhillips, 2012, and 13.5-4.5 MPa (David, 2013) respectively.…”

“…During these in-situ production tests, downhole pressures of the production wells in Mallik, Ignik Sikumi, and Nankai Trough are reduced from 11.2 MPa to 7.3 MPa (Kurihara et al, 2008;Moridis et al, 2011), 8.1-1.8 MPa (ConocoPhillips, 2012, and 13.5-4.5 MPa (David, 2013) respectively. Besides, the downhole temperature of Mallik 5L-38 well maintains at about 343 K (Takahashi et al, 2003;Hancock et al, 2005) to induce the GH dissociation. The in-situ data show that the magnitudes of the pressures and the temperature in the production wells normally stay at (1.8-7.3) Â 10 6 Pa and 3.4 Â 10 2 K respectively.…”