Lifting Heavy Oil from Inactive Well By Hydraulic Lift Systems

Abstract

For the past year, drilling new wells is proving to be more uneconomical for operators due to the oil supply cut down, an agreement between Organization of the Petroleum Exporting Countries (OPEC) and OPEC+ countries, and survey and rig expenses. In such scenarios, artificial lift systems (ALS) are becoming more popular for the ability to maximize production from the existing wells. This technology not only maximizes the current production of any well, but it can also successfully revive the production from inactive wells

The selection of the most suitable ALS in a specific well is crucial for optimal performance. Although a well might have more than one ALS applicable at the same time, an economic analysis will play an influential role besides providing technical solutions. The hydraulic lift is one of the most popular and the oldest ALS for low-pressure wells. On the other hand, the jet pump system is a widely proven ALS in the Middle East and Africa's oil fields. The system can be easily deployed in short time; then, production starts immediately after the well is kicked off.

This paper focuses on lifting heavy oil of 14° API in the northern Iraq region. This directional well 8D was drilled and completed in October 2014 to a total depth of 1,893 m, targeting the Upper Kometan and Shiranish formations. The well did not flow and was abandoned after a few days of the test due to an unsuccessful drill-stem test (DST). Later, in 2019, the well was altered with 3.5 in tubing targeting the Cretaceous formation at a depth of 1,785 m and killed with drilling fluids after workover. Since the oil was heavy, a sliding sleeve door (SSD) was already installed in the completion stage for the future use of ALS. As expected, the well was not able to flow on its own due to oil viscosity and lesser bottom hole pressure. A jet pump was selected as a suitable lift system for this well based on the unloading selector, application, well completion jewelry, and economic analysis.

The well was lifted successfully and produced an accumulative 500 BFPD with around 14% water cut. As the well was not flowing before the jet pump installation, most of the production data was collected during the operation, and the jet pump design was changed accordingly for maximizing production. The production was experiencing emulsions as well, which were treated with chemical injection using the same system. The well was cleaned from drilling fluids until the operator got stable formation fluids, which produced better results. The details of the whole operation are discussed in this paper. The conclusion of this study will assist in the application of a jet pump system for other heavy oil fields as well.