Completion Design for Deep, Sour Norphlet Gas Wells Offshore Mobile, Alabama J.R. McDermott; J.R. McDermott Mobil E and P U.S. Inc. Search for other works by this author on: This Site Google Scholar B.L. Martin, III B.L. Martin, III Mobil E and P U.S. Inc. Search for other works by this author on: This Site Google Scholar Paper presented at the SPE Annual Technical Conference and Exhibition, Washington, D.C., October 1992. Paper Number: SPE-24772-MS https://doi.org/10.2118/24772-MS Published: October 04 1992 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation McDermott, J.R., and B.L. Martin. "Completion Design for Deep, Sour Norphlet Gas Wells Offshore Mobile, Alabama." Paper presented at the SPE Annual Technical Conference and Exhibition, Washington, D.C., October 1992. doi: https://doi.org/10.2118/24772-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu nav search search input Search input auto suggest search filter All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Annual Technical Conference and Exhibition Search Advanced Search AbstractProducing gas from the Norphlet formation in the Mobile Bay Area presents many unique completion design challenges. The Mobile Bay Area Norphlet, a consolidated aeolian sandstone, is estimated to contain an ultimate natural gas resource base of 20 TCF. Proved reserves of 4 – 6 TCF have been discovered to date with hydrogen sulfide concentrations ranging from 50 ppm to 10% and carbon dioxide concentrations up to 4%. Production may also include brine and elemental sulfur. Formation intervals below 20,000' have bottomhole temperatures in excess of 400F and initial bottomhole pressures from 10,000 psi to 20,000 psi. Wells can cost upwards of thirty million dollars to drill and complete due to the extreme depth, the highly corrosive nature of the gas, and the close proximity to environmentally sensitive areas. Economics dictate development with a minimum number of wells on wide spacing, therefore, completions are designed for maximum rate and maximum life.This paper describes the evolution of design concepts and equipment innovations utilized in the completion of Norphlet gas wells in the Lower Mobile Bay - Mary Ann and Mobile 823 Fields.IntroductionThe first Mobile Bay Area offshore leases, Tracts 76-7794-95 (Fig. 1), were acquired from the State of Alabama in October, 1969 for $79,000. Nearly ten years of litigation was required to obtain the necessary drilling permits to drill the first well in Mobile Bay. The original exploration well, drilled on tract 76, to a total depth of 21,113', was spudded in 1978. A 346' net Norphlet gas column was encountered discovering the Lower Mobile Bay - Mary Ann Field. This well was subsequently tested in 1979 at a rate of 12.2 MMcf/D. Compositional analysis revealed that the produced gas contained 8.5% H2S and 3.5% CO2. Production was initiated from the Mary Ann 76–1 well in 1989. To date, approximately fifty Norphlet wells have been drilled in the Mobile Bay Area with an estimated 70% of these finding commercial Norphlet pay.DiscussionThe plan of development for the Lower Mobile Bay Mary Ann Field called for twelve Norphlet completions and peak production of 100 MMcf/D occurring in 1992. Field production was initiated in April, 1998. In 1991, a peak production rate of 100 MMcf/D was realized from only five producing wells. The design concepts and equipment innovations utilized in the Lower Mobile Bay - Mary Ann Field resulted in achieving the production target with significantly fewer wells than planned. The original completion design utilized carbon steel production casing and corrosion resistant alloy (CRA) tubing and completion components. These technologies and completion philosophies were further enhanced and used to successfully drill stem test and complete wells in the Mobile 823 Field, a deeper, higher temperature, higher pressure, lower H2S concentration Norphlet development. In 1990, a new Alabama offshore well test record was set with the Mobile 823 A-3 drill stem test. This well tested at 62.3 MMcf/D with 5017 psi flowing tubing pressure and 150 ppm H2S. Completion operations were initiated at the Mobile 823 Field in 1991. In early 1992, a production rate of 182 MMcf/D was attained from three producing wells.Completion design for the deep, sour Norphlet gas wells in the Mobile Bay Area has evolved over a ten year term. Through that period the goal has been to search out the most effective means and materials to provide the highest production rates without sacrificing reliability or safety.P. 101^ Keywords: production chemistry, valve, spe 24772, upstream oil & gas, resistance, assembly, completion design, sour norphlet gas well offshore, alloy 718, corrosion management Subjects: Production Chemistry, Metallurgy and Biology, Perforating, Completion Selection and Design, Completion Installation and Operations, Completion equipment, Corrosion inhibition and management (including H2S and CO2), Completion Operations This content is only available via PDF. 1992. Society of Petroleum Engineers You can access this article if you purchase or spend a download.
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