Successful Use of Novel Bio-Based Surfactant Internal Ketone Sulfonate (IKS) Chemistry for Indonesian High Temperature Reservoir: Formulation Development to Oil Recovery Efficiency in Native Reservoir Core

Abstract

Growing national demand and declining or maturing fields in Indonesia have pushed the country to increase and accelerate efforts to improve production from the maturing fields by engaging various tertiary recovery techniques as one of the strategic pillars in achieving national target of 1 MMBOPD oil production in 2030. Several fields are being considered and being studied strategically as potential for application of chemical EOR technologies. High temperature reservoirs in Limau block of South-Sumatran basin is an onshore mature field which has been identified as a potential chemical EOR candidate. Due to higher reservoir temperature (>100°C) it is always challenging to develop a surfactant-based chemical EOR solution due to pronounced issues in chemical compatibility. For any economical surfactant-based chemical EOR process an optimized surfactant or surfactant-polymer formulation needs to be developed in a laboratory which depicts good thermal stability, compatibility with polymer or injection water, exhibits ultra-low interfacial properties (<10−2 mN/m) with crude oil and injection water brine, lower surfactant adsorption and higher production of residual oil from the native reservoir core using shorter slug (< 1 PV of SP injection). In this current study, a detailed workflow was followed to successfully achieve the above key performance indicators (KPIs) for developing a tailor-made surfactant-polymer formulation in a high temperature (107° C) Limau field, which is always a massive challenge. A multi-component surfactant formulation using the novel bio-based surfactant internal ketone sulfonate (IKS) as the primary surfactant was designed for high-temperature Limau reservoir. The detailed laboratory analysis shows that surfactant formulation along with polymer is able to exhibit a robust behaviour at the challenging reservoir condition. The detailed laboratory screening concludes that the designed robust SP formulation is able to induce ultra-low IFT (~1×10−3 mN/m), excellent solubility and compatibility at the injection water salinity, high incremental oil recovery (>75% ROIP) with low surfactant retention in shorter SP slug injection in reservoir core.