Gulf of Mexico Gas Hydrate Joint Industry Project Leg II: Alaminos Canyon 21 Site Summary.

摘要

The primary goal of the Gulf of Mexico Joint Industry Project (JIP) Leg II drilling program was to locate and record the occurrence of gas hydrate in high-quality deepwater sand reservoirs. In the first week of May 2009, the JIP utilized the Helix Q-4000 semi-submersible to drill and log two wells in the Diana sub-basin in the northwestern Gulf of Mexico at the Alaminos Canyon (AC) 21 site. The AC 21-A and AC 21-B wells confirmed the presence of an areally extensive, sand-rich deepwater fan system that was predicted from industry 3-D seismic data and existing industry well penetrations. The primary targets were encountered within 600 ft of the seafloor, well above the predicted base of gas hydrate stability depth of approximately 1,500 feet below sea floor (fbsf). The target sand reservoirs as seen in the A and B wells measured 62 ft and 125 ft, respectively, and contained elevated formation resistivity consistent with low to moderate saturations of gas hydrate (20% to 40%). The interface between the overlying shales and the hydrate-bearing sands is one of high acoustic impedance, thus providing an anomalous response on the 3-D seismic data with a strong peak-leading top.