Anti Paraffin Agent Stimulation to Increase Injection Rate in NP-082 Injection Well, Lirik Field Pertamina EP

Abstract

Water management is crucial in the oil production planning and development. Supported with adequate production facilities, injection well is required to reinject produced water from production well after appropriate treatment in surface. Without adequate injection well, number of wells and ability of wells to inject produced water, oil production can be a separate problem. The ability of an injection well to inject produced water is important to note, proven with its sufficient injection rate in particular wellhead pressure. Unfortunately, some injection wells may have any borehole problems that reduce its ability to inject produced water. Paraffin may occurs, and block the flow of injected water in that well. This paper aims to deliver an effective solution on how injection rate can increase in the parffinic injection well using anti-paraffin agent stimulation. In Lirik Field, anti paraffin agent stimulation is applied in NP-082 injection well. 958 barrels water per day (bwpd) is the initial injection rate with 150 psi of wellhead pressure of this well before stimulation. Due to its conversion from production well into injection well historically, oil slug is estimated to occur in perforation zone of this well. Moreover, paraffinic oil is produced in North Pulai structure. Anti paraffin agent injection is then applied to dissolve the paraffin in the perforation area. Anti paraffin agent, an additive, is able to break the paraffin contaminant in wellbore. Operational procedure is applied, injection pressure may not exceed the fracturing pressure on this well. Pre-treatment IRT is applied to compare with IRT after treatment. Increasing IRT before and after the treatment indicates its success. Post-job IRT is applied with various wellhead pressure and rate. Before treatment, injection rate varies from 0.5 – 0.75 bpm at 290 to 350 psi of wellhead pressure. With similar wellhead pressure, injection rate increases up to 1.75 bpm. Even in maximum pressure of 500 psi, injection rate could reachs 3.5 bpm. It indicates the stimulation in NP-082 well succeed to increase injection rate. This well is now operated at 280 psi of wellhead pressure with 1500 – 1600 bwpd of injection rate. Anti paraffin agent stimulation becomes effective way with paraffinic problem in injection well.