HYDRATE CORE DRILLING TESTS

• Main Authors: John H. Cohen, Thomas E. Williams, Ali G. Kadaster, Bill V. Liddell
• Language: unknown
• Published: 2012
• Subjects: 02 PETROLEUM; 03 NATURAL GAS; CORE CATCHERS; DEPOSITION; DESIGN; DRILLING; DRILLING EQUIPMENT; DRILLING FLUIDS; HYDRATES; METHANE; MIXTURES; PERMAFROST; PETROLEUM; PRODUCTION; SAND; VISCOSITY; Arctic; Ice; Methane hydrate; permafrost
• Online Access: http://www.osti.gov/servlets/purl/811812; https://www.osti.gov/biblio/811812; https://doi.org/10.2172/811812

The ''Methane Hydrate Production from Alaskan Permafrost'' project is a three-year endeavor being conducted by Maurer Technology Inc. (MTI), Noble, and Anadarko Petroleum, in partnership with the U.S. DOE National Energy Technology Laboratory (NETL). The project's goal is to build on previous and ongoing R&D in the area of onshore hydrate deposition. The project team plans to design and implement a program to safely and economically drill, core and produce gas from arctic hydrates. The current work scope includes drilling and coring one well on Anadarko leases in FY 2003 during the winter drilling season. A specially built on-site core analysis laboratory will be used to determine some of the physical characteristics of the hydrates and surrounding rock. Prior to going to the field, the project team designed and conducted a controlled series of coring tests for simulating coring of hydrate formations. A variety of equipment and procedures were tested and modified to develop a practical solution for this special application. This Topical Report summarizes these coring tests. A special facility was designed and installed at MTI's Drilling Research Center (DRC) in Houston and used to conduct coring tests. Equipment and procedures were tested by cutting cores from frozen mixtures of sand and water supported by casing and designed to simulate hydrate formations. Tests were conducted with chilled drilling fluids. Tests showed that frozen core can be washed out and reduced in size by the action of the drilling fluid. Washing of the core by the drilling fluid caused a reduction in core diameter, making core recovery very difficult (if not impossible). One successful solution was to drill the last 6 inches of core dry (without fluid circulation). These tests demonstrated that it will be difficult to capture core when drilling in permafrost or hydrates without implementing certain safeguards. Among the coring tests was a simulated hydrate formation comprised of coarse, large-grain sand in ice. Results with this core ...