Affiliation:
1. PETRONAS Research Sdn Bhd, Malaysia
2. PETRONAS Carigali Sdn Bhd, Malaysia
Abstract
Abstract
Several oil fields in the Malaysian oilfields have experienced sand production issues, which caused a reduction in production. Moreover, if artificial lift systems such as ESP is installed, it can lead to frequent failures, which will have a significant impact on cost due to pump downtime. Mechanical solutions that are commonly used, such as sand screen and gravel packs, are suboptimal because they decrease inflow area and make optimization activities difficult. This paper describes an integrated solution that employs inhouse sand agglomeration chemical (SAC) technology and mechanical solution to address the sand production problem from laboratory to pilot in an offshore oil well.
Extensive laboratory tests confirmed the SAC viability for sand production in Field-S. A pilot well candidate was selected based on a history of frequent well interventions due to sand production in the past, as well as the completeness of core samples, mineralogy data, and fluid samples. The test was conducted with an actual downhole sand sample and a sand screen, while flowrate and pressure were monitored. Produced sand was collected for particle size distribution measurement and scanning electron microscope, static and dynamic thermal stability tests, chemical and agglomerated sand particles were aged at downhole temperature and pressure. During pilot, the SAC was injected near the wellbore, and then a sand screen was installed, with post-injection monitoring.
A novel multipolymers chemical concept SAC was proposed, which provides larger agglomerates of grains sands and stronger bond strength between particles, resulting in longer agglomerated sand particle longevity. Meanwhile, the sand screen was installed, and injection was done simply with a bullhead and no squeeze required. After applying SAC in the laboratory, a strong sand agglomeration was observed on the produced sand sample. The SAC can reduce the non-uniformity of agglomerated sand particles, lowering the risk of screen plugging and improving permeability. It also reduces the risk of sand screen plugging and opens more flow channels for hydrocarbon to flow through.
This first pilot was successfully executed in a well at Field-S. The knowledge and experience gathered during this first pilot will be utilized as a reference for future replication to other candidates in the Malaysian oilfields with similar issue.