High Molecular Weight Organic Scale; A Sticky Journey in Finding the Solution

Abstract

Flow assurance has been a big focus of oil and gas operation in ensuring the delivery of the targeted production. A few fields located offshore Malaysia have been experiencing solid deposition inside tubing and stable micro-emulsion from early stage of their life. Oil production from Field W begin in January 2003, unfortunately the wells produced viscous stable emulsion which caused the production decline significantly. Multiple analyses and efforts, including chemical and mechanical treatments, conducted over the years with minimal success. The damaging mechanism was determined to be caused by rare organic deposit that have caused a significant pressure drop in the tubing, which consequently restrict oil production and tested to only disperse at above 90°C. It was suspected that the organic deposit was a naturally occurring component of the crude oil itself, separating from the bulk of the crude as a consequence of the fluids movement towards the wellbore and the consequent drop in fluid pressure. This paper focuses on the step-by-step workflow developed to identify the solid deposition, laboratory testing, treatments conducted and the result of different chemical treatments in Field W. The ultimate effort was by developing an advanced eco-friendly nano-fluid to remediate the rare issue of High Molecular Weight Organic Deposit (HMWOD) in the fields. The nano-fluid pilot treatment was conducted in 2014 and successfully rejuvenate the well with total of 20,000bbl incremental oil volume. Early 2018, subsequent treatments were conducted that contributed substantial improvement to the field production and at lower total treatment cost. This advanced chemical using nano-fluid technology concept is deemed feasible and will be further replicated in other fields. This paper is highly beneficial to Operators, Petroleum and Flow Assurance Engineers experiencing flow assurance issue on organic scale such as microcrystalline wax, high molecular weight wax and stable emulsion in the crude production. This paper also promotes the use of nano-fluid technology as part of the solution to flow assurance issue in Oil and Gas industry.