High-Density Polyethylene Liner Safeguards Against Corrosion and Wear

Abstract

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 199000, “High-Density Polyethylene Liner: Successful Alternative Against Corrosion and Wear Problems in Production Tubing of Mature Fields in Colombia,” by Gloria Isabel Duarte Poveda, Miguel Mateus Barragán, and José Alexander Estévez Lizarazo, Ecopetrol, et al., prepared for the 2019 SPE Latin American and Caribbean Petroleum Engineering Conference, Bogota, Colombia, 5-7 June. The paper has not been peer reviewed. Production tubing in mature fields in the Magdalena Department’s Middle Valley in Colombia has shown a run life between 180 and 300 days, with failures mainly caused by corrosion and abrasive wear or friction mechanisms. Extended use of high-density polyethylene (HDPE) liner in flow and collector lines with corrosion and abrasion problems has resulted in positive results. The complete paper presents the results of evaluation of laboratory and demonstration trials of HDPE liner to mitigate premature failures and prolong the run life of production tubing. Introduction Root-cause analysis determined that failures in production tubing in the mature Casabe and Cantagallo fields could be the result mainly of corrosion by the multiphase fluids transported or as the result of wear mechanisms caused by contact between the internal wall of the tubing and the sucker rod in artificial-lift systems. To solve this problem, HDPE liner was evaluated in the laboratory and implemented in a pilot-scale test. Results proved its ability to absorb abrasion impact from sand particles and resist CO2 corrosion. After 12 months in service, the HDPE liner demonstrated its compatibility with aggressive fluids, remaining thermally stable with no structural variation and absence of swelling, softening, and blistering. After 6 years, the pilot remained failure-free and operationally active. On the basis of these results as well as other research in the literature, HDPE liner was proposed as a downhole alternative to prolong run life of critical wells in the Casabe field. To this end, HDPE lining for carbon steel tubing was developed and manufactured in Colombia through an engineering process that included materials specification, prototype design, mechanical stress analysis, laboratory tests in simulated downhole conditions, redesign of the prototype, and optimization of the production process. To validate the technology, the downhole HDPE liner was installed in three producing wells with progressive-cavity-pump (PCP) artificial-lift systems and a run life of approximately 300 days. After 400 days of service, well intervention was performed not related to tubing; the tubing had not experienced damage and was reinstalled, with a three- to sixfold run-life increase. HDPE Liner Technology HDPE is known for its ability to inhibit corrosion, improve flow fluid because of a lower friction coefficient compared with carbon steel, and resist abrasive wear because of high tenacity properties. The HDPE (PE-100) is used in contact with multiphase fluids (water/crude oil/gas) with maximum service temperature of up to 60°C, depending on the manufacturer. According to laboratory tests, the resistance of HDPE to abrasive wear and corrosion is approximately three times that of carbon steel.