A Novel Epoxy Resin Composition as a Lost Circulation Material: Formulation, Lab Testing and Field Execution

Abstract

The novel resin composition described in this paper has been designed to treat moderate to severe losses. The resin composition comprises an epoxy resin and a chemical activator that undergo a polymerization reaction without any addition of water. The polymerization was designed to delay and successfully controlled to gel up and form the target resin composition after the fluid goes inside the wellbore. This is very important to avoid early setting of the fluid. The objective of this paper is to discuss the formulation of epoxy resin as a lost circulation material and also detail the lab testing and field execution. In this study, we used two different epoxy resins to study the development of the novel loss circulation material. One contains two epoxy groups and the other contains only one epoxy group. Two different chemical activators have been used in this study as well; each of them differs in the number of amine groups and geometry. The effect of these differences on the polymerization in terms of time and properties were investigated. In addition, the effect of the chemical activator concertation on the setting time of the resin composition was investigated to accomplish a controlled and a delayed polymerization. Also, the chemical conditions were evaluated to simulate a variety of downhole conditions to prove the effectiveness of this novel resin composition as a loss circulation treatment. The lab testing includes thickening time measurements. The novel resin composition is designed to have a controlled thickening time under a variety of downhole conditions. This is important to have an accurate placement of the fluid inside the wellbore; thus, avoiding an early setting of the fluid. We found that the thickening time of the resin composition can be controlled by mainly varying the concertation of the chemical activator. We found as well that changing the type of epoxy resin or chemical activator produce different gelling time and properties. We designed the loss circulation composition to provide a predictable and controlled pumping time. This novel resin composition can remain in a liquid phase from a few minutes to several hours based on the desired conditions. This is favorable in order to have an accurate placement of the fluid inside the wellbore over a predictable and controlled period of time. The final and target resin composition, will appear and gel as a solid thereby preventing loss circulation. The resin was pumped from the BHA in a single stage which helped mitigate and reduce the dynamic losses from 260 bbl./hr. to 200 bbl./hr. using only 25 bbls and eventually to zero.