Publications

ExxonMobil Cepu Limited (EMCL) operates the Banyu Urip field (BU), one of biggest oil producers in Indonesia. As of the end of 2020, field production has been declining. Several efforts have been conducted in order to optimize production, both on the surface and subsurface side such as perforation, acidizing, gas lift installation, etc. Common approach to optimize oil production is to maximize the well choke opening up to 100%, whilst accounting for various factors such as water content and gas/oil ratio. However, the existing choke cage has a tiny hole or perforation (flow path) that results in a higher pressure drop (dP) increasing probability of scale build up across the choke. This is primarily caused by the choke cage design. Recognizing the accessible room of improvement on particular wells, an initiative to modify the choke cage in-house was undertaken.

This paper aims to share the journey (EMCL experience ) of the cage alterations, challenges encountered, and strategies on how to operationalize the idea with the objective to overcome flow restrictions across chokes, without compromising the integrity of the choke bodies and adjacent equipment. The main challenge when having such modification is the occurrence of erosional damage due to flow impingement to the inner side of choke body. Modification is limited to the cage hole size and patterns using available critical spare parts to suppress the costly investment. By enlarging the cage hole and determining the suitable design, the pressure drop across choke can be reduced from approximately 100 kPa-g by up to 500 kPa-g and successfully yields the oil production within BU Facilities up to 1000bpd net-oil per well depending on its productivity index.