ENSURING STABLE OPERATION OF GAS COLLECTION SYSTEM IN CONDITION OF REDUCED WELL PRODUCTION

International Conference on Innovations and Prospects of Development of Mining Machinery and Electrical Engineering 2018

矿业工程;电工学

Krasnov, A.N.^1 ; Prakhova, M.Y.^1 ; Khoroshavina, E.A.^1

Ufa State Petroleum Technological University, Russia^1

关键词: Critical velocities;    Gas;    Liquid mixtures;    Gas collection systems;    Gas processing plant;    Gas-condensate fields;    Heat exchange medium;    Innovative technology;    Thermobaric conditions;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/194/7/072005/pdf
DOI  :  10.1088/1755-1315/194/7/072005

来源: IOP

【 摘 要 】

Any gas condensate field has an extensive gas collection system (GCS), through which gas is delivered from the wells to a Gas Processing Plant by means of reservoir energy. At the final stage of field development the GCS operating conditions undergo significant changes, in particular due to lower temperature of transported gas and increased water cut in the production fluid. In winter, simultaneous action of these factors may lead to formation of ice and hydrate plugs disrupting normal operation of the GCS. Gas stream velocity shall exceed so-called critical velocity to ensure that the flowlines operate in the liquid removal mode. Its value is determined by a pipeline diameter, ratio of gas and liquid density, thermobaric conditions, flowline slope and other factors. Ensuring necessary velocity at the final stage of operation is usually impossible, thus, complete moisture removal is problematic and the hazard of ice formation persists. This paper proposes an innovative technology providing stable GCS operation by preventing ice formation in the flowline. For that end, the gas-liquid mixture in the GCS gets additional heat from heat tracing located inside the GCS. The heat tracing is coiled tubing with constant circulation of liquid heat-transfer medium: methanol-water solution, heated by rejected heat when passing through the air cooler unit (ACU). The coiled tubing forms a closed loop with the methanol pipeline. Changes in heat exchange medium consumption are introduced with a VSD-driven pump, basing on the results of temperature measurement in the flowline. Application of the proposed technique allows not only providing emergency-free GCS operation, but recuperation of rejected heat from the ACU as well.