Research On Mixed Transportation And Treatment Of High Pressure Oil And Gas In SH Field

SH oil and gas field is a recently exploited and developed block of A oil company.Due to the wellhead oil pressure of the SH field can be sTable at a higher level(above 10MPa)currently,the mixed transportation of oil and gas under medium and high pressure conditions can be considered.However,the problems such as gas hydrate will effect the development of oil and gas field in the process of mixed transportation.Therefore,it is greatly important to study the mixing process for the medium and high pressure pipelines and the treatment for natural gas.The effect of inlet pressure,the diameter of pipelines,the thickness of insulation layer and gas-oil ratio on hydrates formation in mixed pipelines are studied.The process parameters of oil and gas gathering and transportation pipelines are determined.Where,the inlet pressure is 4MPa,the design pressure of the gathering pipeline is 6.4MPa,the thickness of insulation layer is 30 mm,the gathering radius of DN65 and DN80 pipeline are 7.3 km and 6.6 km,respectively.The continuous flexible composite pipes are selected for single well gathering pipeline and L245NS+HBPE lining material or L245+inner coating are chosen for inter-station pipeline.Two treatment programs of sulfur and acid gas removed from associated gas are developed.Through the comparison between technology and economy,the process of MDEA + Claus sulfur recovery/tail gas treatment is used for the removal of sulfur and acid gas.Through compared the technical charateristics of different dehydration methods,the process of molecular sieve is developed.Through calculated and compared the payback period for four light hydrocarbon recovery programs,4MPa inlet pressure propane pre-cooling + expander mixed refrigeration is applied for the light hydrocarbon recovery.Besides,the sensitivity analysis is performed for light hydrocarbon recovery by HYSYS software.The effects of inbound process parameters,process parameters of low temperature separation unit and process parameters of light hydrocarbon fractionation unit on the ratio of light hydrocarbon recovery and energy consumption are studied.So,the optimal operating parameters are determined.At the same time,natural gas,liquefied petroleum gas and light oil are in line with the corresponding national standards.