Modeling Heat Pump Technology for Economically Attractive Decarbonized Oil Production Systems

Abstract

Many operators with large stakes in unconventional shale oil plays have published targets to drastically reduce emissions with some considering carbon emission tax for economic evaluations of future projects. This creates the need for finding electrically powered alternatives to replace equipment that currently consumes fuel gas, such as fired heaters. Production facility designs for unconventional shale must be simple, robust and require relatively low CAPEX and OPEX to be economically viable. This poses a challenge for electrically powered alternatives because fuel gas is freely available at production systems, whilst electricity comes at a cost. To address this challenge, novel fully electric production system designs have been developed based on heat pump technology. The practical and economic feasibility for these designs are evaluated and demonstrated so that these can be considered as realistic solutions for future projects. The major reasons why crude oil must be heated at upstream production facilities are to break potential emulsions of oil and water and to stabilize the oil. Stabilizing the oil means that volatile components are removed from the crude, so that it can be transported and stored in tanks without emission and safety concerns. The novel production systems achieve this by pairing a single stage electrically driven heat pump with heat integration. The novel production system designs are analyzed using steady state and dynamic simulations employing industry accepted process simulation software. The steady state simulations generate metrics such as energy consumption, estimated emissions and hydrocarbon recovery which are used in conjunction with emission factors and other economic factors to compare the performance to standard production facilities. The dynamic simulations are used to demonstrate the feasibility for starting-up and controlling the facility for this novel technology application. The simulation results demonstrate that the heat pump based designs consume around 70% less electrical power compared to direct electrical heating. Further benefits are that the temperatures can be controlled at various stages in the process to substantially increase the facility's oil recovery. This also results in leaner gas, which is particularly attractive for facilities that include gas compression and dehydration. The increased oil recovery results in substantially higher revenue which leads to an economically more attractive design compared to a traditional facility, even without taking carbon emission tax into consideration. These comparisons are provided for different types of facilities during different production scenarios during varying weather conditions.