Boosting Production from Low Pressure Wells and Reviving Dead Wells Using Surface Mounted Technology and Avoiding Well Intervention

Abstract

Innovative Surface Jet Pump (Velocity SpoolTM) technology combined with novel compact separation was tested at a remote onshore wellhead location to see if it could increase multi-phase production from low pressure oil wells that were already producing and revive wells that were backed out/not flowing. The technology was mounted on the surface, not downhole and avoided well intervention, The Surface Jet Pump (SJP) is a passive device which utilises often wasted fluid energy (via choke) from a high pressure (HP) well to reduce the back-pressure of a low pressure (LP) well and boost its’ flow to the production manifold. In multi-phase oil applications where there can be significant amount of gas present, a compact in-line separator (called I-Sep) is installed upstream of the SJP to bulk separate the gas and liquid fluids and allow the liquid motive fluid to be directed to the SJP. For this trial, one of Caltec's patented SJP multiphase skids was installed at an onshore wellhead location and connected to existing HP and LP wells. Production from both wells was diverted to the SJP to test its effectiveness. The trial tests lasted 3 months. Results from the first set of tests showed that the SJP boosted production from a multiphase LP well that was already flowing by an additional average of 380 bbls/d with a corresponding wellhead pressure reduction of 45 psi. Results from the second set of tests showed that the SJP revived a dead well that had not been flowing since 2004 and made it flow at an average rate of 1092 bbl/d with a backpressure pressure reduction ranging from 54 to 27 psi. Prior to the trial, several attempts had been made to bring this dead well back into production using other methods but these were not successful. The results showed conclusively that the SJP was very effective in boosting production from LP oil wells. The production gain was achieved by lowering the FHWP of the well and the amount of gain was dependent on the productivity index of the well. The advantages that the SJP offers over any conventional technologies such as Multi-phase pumps and ESPs are several: it is tolerant to variations in flow conditions, gas volume fractions (GVF) and associated slugging (without affecting performance), it is surface mounted (so well intervention is not required), low cost, easy to deploy, has no moving parts, consumes zero fuel gas/electrical power and uses already available surplus energy. This paper reports the trial results and discusses the use of Surface Jet Pumps as an alternative to other boosting methods for oil production. The design and operational criteria of the SJP are also highlighted.