One-Trip Chemistry Activates a Polymer and Cleans a Drilling Fluid Filter Cake at Once

Abstract

An innovative sand control technology is being developed that has the capability to conform to the wellbore and apply a positive stress on the formation face. The technology is a porous shape memory polymer with the capability to change geometric shapes. This shape memory polymeric material is molded to an initial geometric shape. The material is then heated and compacted to a smaller volume, 25% of initial volume compacted, for run-in hole (RIH) geometry. As any shape memory polymer, it can recover its original shape if heated close to its Tg, or by temporarily chemically shifting its Tg to a new lower temperature that of its original Tg. This paper will present the results of additives added to completion fluids, giving the final fluid composition the ability to activate the polymer to its original shape, and simultaneously clean up the filter cake left by the drilling fluid before the polymer reaches the wellbore. The additives are delayed so that the filter cake retains fluid loss properties during activation, but breaks shortly after the polymer reaches the gauge-hole, or has enough treatment caused by the one-trip fluid there by allowing for production at maximum flow rates. At the same time that the filter cake is being treated, a second additive is acting as a plasticizer on the shape memory polymer to activate it, forcing the polymer to recover its original shape. The results are measured via two test methods, one that monitors and records the activation time of the polymer to gauge hole, and a second method that measures the fluid loss properties of the filter cake ensuring that the filter cake is stable for the time required for the shape memory polymer to reach gauge hole.