Achieving Remarkable Long ESP Run Life Exceeding 9 Years Continuously in Brown Oil Field Thru Leak Free Production in Highly Corrosive Environment

Abstract

A very interesting case in mature field in Egypt, has embarked on a project of replacing Oil Production wells, originally constructed with API 5L carbon steel pipe, with fiberglass lined API 5CT Threaded and coupled tubing. Previously, all wells had a conventional EUE carbon steel string producing with different ranges of production within 600 - 3000 bbls/day of oil without water production in early stage of the field. Later on, water injection commenced in 2004 in order to arrest reservoir pressure decline and increase the oil offtake. Accordingly, the water production progressively rose since in 2011 the measured water cut was up to 90% of with much salt content as high as 330,000 ppm, and fully saturated with dissolved oxygen. As a result, the field has been facing severe corrosion related failures in Carbon steel strings in producer wells. Furthermore, the problem has been escalated and the average pull out of hole workover jobs of each well reached two times per year due to tubular failure resulting from corrosion. The tubing leakage failure increased the OPEX of the field by which impacted negatively on the value of the asset. Many actions had been taken attempting to sole or at least reduce the severity of the problem such as; using 13% Chrome steel tubing, and placing down hole injection of corrosion inhibitor chemicals. But each solution has a drawback and the improvement in the runlife of wells were below expectations. Upon all the above repeated workovers were done to replace the frequently leaked tubing, affecting on the field performance. GRE lining technology proved as the best erosion and corrosion resistance method that save ell integrity with the lowest cost in the field of discussion where the water salinity is 330,000 ppm, high dissolved oxygen, high temperature, and high co2 up to 6%. Three wells were chosen as trial to be completed using Glass Reinforced Epoxy (GRE) lined tubing for internal corrosion protection. However, one of these wells has lasted for over nine years of continuous production without the even ESP fails. Such positive results of achieving Outstanding Performance in attaining longer tubing life with less workover operation with very cheaper technology. Afterwards, the company decided to try 3%Chrome tubing for the oil production wells with a premium thread connection. In this paper, we will demonstrate the pros and cons of utilizing such a material and connection failure. Guided by the successful trail, a shift in the inventory was done toward such application that turned up the economic value of the field. Special components were engineered to provide a transition between GRE lined tubulars and plain end unlined fittings and flanges. This paper chronicles the history of the Oil Production, the nature, reasons and consequences of the multiple corrosion failures and the failed corrosion mitigation strategies. It will highlight the reasons why this specific well lasted for 9 continuous years and the root cause leading to the ESP consistent performance during this period, unlike the other bare steel wells. Furthermore, the paper will shed light on the techno-commercial analysis and engineering that forms the basis for this mammoth effort.