Mineral Scale Control in a CO2 Flooded Oilfield

Abstract This paper presents a case study of improving scale inhibition treatments in the Sharon Ridge Canyon Unit (SRCU), West Texas in response to the increased scaling conditions that has arisen from carbon dioxide (CO2) injection into the oil reservoir. In anticipation of increased scale deposition, a proactive approach was taken by carrying out a comprehensive field system analysis and scale survey prior to the commencement of CO2 flooding at SRCU. This analysis/survey was intended to assess the new situation and come up with a cost effective scale treatment program. A laboratory evaluation of a number of scale inhibitors was then carried out. Based on our understanding of the problem and the lab evaluation results, a new scale inhibitor and a new chemical treatment program were developed and implemented in the field. This paper describes the system analysis/scale survey and highlights its importance in understanding the changing situation and the new challenges in scale inhibition arising from CO2 flood. The laboratory evaluation for identifying the most suitable and cost-effective inhibitor is then briefly described. The paper then discusses the new scale inhibition treatment program and scale monitoring program. The field results from implementing the new treatment program are presented and discussed. Owing to the proactive approach and the improved inhibitor and treatment, the field production system and water re-injection system have not been troubled with scale deposition.