Heat Transfer Coefficients for Gas Well Flow Lines On the Bottom of the Gulf of Mexico

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. This paper was prepared for the Annual Fall Meeting of the Society of Petroleum Engineers of AIME, to be held in Houston, TX, Sept. 29-Oct. 2, 1968. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made. provided agreement to give proper credit is made. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines. Heat losses must be considered along with other variables such as flow rates, gas composition and liquid content during the design of production installations in the Gulf of Mexico in order to prevent operating problems due to hydrates forming in gas well flow lines between individual wells and central production facilities. Heat losses average two BTU's per linear foot of line per degree temperature differential between the gas temperature at the well, the central production facility and Gulf water temperature. Flow lines that are buried have heat losses of one or less and lines that are uncovered have heat losses of three. Where lines are uncovered and risers extending from the bottom of the Gulf up onto the production platform are uninsulated, heat losses approach four. Heat losses become critical during winter months when Gulf of Mexico water temperatures fall below 70 degrees F. This paper is presented to benefit the industry with a basis for estimating heat losses during the design of future installations and revamping of present installations. Introduction The problem confronted was the loss of heat in gas well flow lines between individual wells and central production facilities resulting in the formation of hydrates which plug the lines and stop the flow of gas. The problem becomes acute during winter months when the Gulf of Mexico water temperature falls below 70 degrees F. Winter is also the time of maximum gas demand so losses in gas production due to plugged flow lines result in losses of revenue larger than any other time of the year. The heat losses were determined by observing temperatures at the individual wells, the production platform and the surface and the bottom of the Gulf of Mexico waters. observations were made under a wide variety of conditions but usually were made as part of routine production activities. one series of observations were made under controlled test conditions. All results compare favorably. DESCRIPTION OF EQUIPMENT AND PROCESSES USED Flow line temperatures were taken in liquid filled tubes taped to the lines above the water.