Sustaining Oil and Gas Fields by Using Multiphase Gas Compression to Increase Production and Reserves, and Lower Operating Costs and Environmental Emissions Footprint

Abstract

A multiphase compressor has been developed that provides: compression ratios up to 40:1, the ability to handle multiphase and slugging flow, and a very broad and flexible operating range allowing it to be positioned near the wellhead. Currently the product is targeted at onshore unconventional fields, and field data have been collected on such fields. For deployment to onshore unconventional fields the multiphase compressor has been packaged within a system so that it is easily transportable and fully self-contained, requiring no external power source or utilities. Also, minimal effort is required to tie in at the wellpad (just process connections in and out), no downhole intervention is needed, and typically no site preparations are required, which allow it to be easily relocatable with minimal sunk investment cost. Onshore applications include: Artificial lift from surface to increase production and reserves, and reduce operating costs – applicable to both oil wells with moderate quantities of gas present, and gas wells suffering from liquid loading. Field data show production enhancement of up to 300% versus alternative forms of artificial lift. ‘Frac hit’ recovery to restore parent well production more quickly (by accelerated recovery of preload or ‘frac hit’ fluids from parent wells) – applicable to both oil and gas wells. Field data show accelerated fluid removal versus alternative forms of artificial lift and reservoir studies indicate around an order of magnitude faster recovery of fluids. Lower methane and CO2 emissions and operating costs from field operations – operator intensive flowbacks to open top tanks to kick wells off can instead be achieved with the multiphase compressor, which also avoids the methane emissions to the environment associated with open top tank flowbacks or CO2 emissions from flaring. Lower methane and CO2 emission field development options – by enabling multiphase gathering to centralized facilities, the emissions associated with poor pad separation and the associated fugitive emissions from on-site storage and movement of volatile liquids can be eliminated, and at the same time eliminating operating costs associated with intensive distributed operations such as road tanker export of oil from wellpads. Additionally, abandonment of late life conventional oil and gas reservoirs and wells can be deferred by avoiding slugging well flows for longer – adding both production and reserves, and removing the operating cost associated with kicking off wells. For land conventional well applications the same multiphase compressor and package can be deployed as for unconventional fields – and the system packaging can be easily adjusted to deploy to offshore platforms. The multiphase compressor has also been redesigned for subsea, and uses the same principles of operation to provide unique benefits for subsea applications: particularly for late life gas wells to add more production and reserves than would be possible from existing subsea multiphase boosting. Operators will be able to deliver more production and reserves from their existing assets, reduce operating costs, and lower environmental emissions from their production operations.