Successful Application of Jet Pump Technology for Production Optimization in a Brown Oil Field - A Case Study in Pakistan

Abstract

Artificial lift systems (ALS) are among the most extensively used production techniques in global oil and gas operations. Wells that cannot produce liquids to the surface through their own pressure require lift technologies to enable the production. In this study, a poor-boy gas lifted well was replaced with a jet pumping system to enhance the production. The software analysis, jet pump (JP) installation, and operational results are presented to validate the utilization of technology.

The candidate well was spud in October 1983 and produced an average of 3,200 BOPD and 1,000 BWPD at flowing wellhead pressure (FWHP) of 2,300 psi from two formations with a slotted-liner in an open hole. However, due to an increase in water production and excessive drop in the FWHP, oil production dropped to zero. The well was brought back to production with the help of a poor-boy gas lift system after making hole punches in the tubing string. But it flowed intermittently with marginal production. A jet pump was recommended as the best lift method based on the technical analysis for ALS. The JP can easily handle a wide range of production and doesn't require rig assistance for JP retrieval and overhauling in case of any changes in future wellbore conditions. Therefore, the well was reconstructed with a 5 inch liner and completed with 3-1/2 inch tubing with a bottomhole assembly (BHA) for JP.

After the workover job, the operator tried to revive the well with poor-boy gas lift technology by injecting gas into the casing annulus which passes through the ports of the jet pump's BHA into the tubing. Nevertheless, it failed to lift the well because of excessive hydrostatic head. Thus, a jet pump was brought in to revitalize its life. Based on software analysis, a high-volume jet pump was designed with 12A Nozzle/Throat combination and run in hole with a free-style JP. In the beginning, surface injection pressure and rate were kept low to kick off the well. When production became stable and oil cut increased, pumping parameters were increased gradually while monitoring daily production. These techniques helped to optimize production by tuning injection parameters at the surface. The well was revived to a producing rate of 1,240-1,290 BFPD with 45-50 BOPD at 98% water cut and injection rate and pressure of 3,350 BPD and 3,700 psi, respectively. The main benefit of the free-style JP was that it deployed and retrieved hydraulically without requiring slickline intervention.

In summary, jet pump was a proven well activation and lift solution for the candidate well. There are similar cases in the Middle East and North Africa (MENA) region and globally. In this case, JP technology was found to be an effective replacement for a poor-boy gas lifted well and helped the operator enhance production of the depleting brown oil field.