A Novel Temperature-Activated, Rigid-Setting Material: Case Histories and Lessons Learned After More than 500 Well Interventions for Drilling and Conformance Applications
Authors: Vasquez Julio , Fowler Ian 
Published: June 2014

Abstract
This paper discusses the field application of an innovative temperature-activated, rigid-setting fluid (RSF) that has been used extensively during drilling, completion, and production stages of hydrocarbon producing wells. Severe lost circulation during drilling operations is often encountered when the well is drilled overbalanced through high-permeability, fractured, or easily fractured formations. In cases of severe or total lost circulation, conventional lost-circulation materials (LCMs) sometimes fail to provide an adequate solution. The RSF system has proven successful for curing severe dynamic and static losses by pumping treatments through the drillstring bottomhole assembly (BHA) (no trip out required) and taking advantage of its highly controllable fast setting properties. In addition to drilling applications, this system has also been widely used to shut off undesired fluid production (water or gas) during workover interventions in extreme cases where conventional cement slurries or polymer gel systems have yielded a low success ratio.
The RSF system is a temperature-activated, rigid, fast-setting fluid that exhibits a unique set of properties. This paper details the specific chemical and mechanical characteristics and field performance of the system. The RSF system is a rigid inorganic "cement-like" setting material that has an exothermic right-angle set. It can undergo a phase change from liquid to an unpumpable clay-like consistency in a matter of minutes with zero static gel, with a predictable and reliable activation time. Unlike cement, the RSF system is capable of rapidly developing high compressive strength (∼4000 psi in less than three hours), creating a plug capable of withstanding high differential pressure and significantly reducing intervention times. Additionally, laboratory testing has shown that the RSF system is able to tolerate up to 50% contamination with oil and/or water-based drilling fluid and still set hard with a controlled set time. The RSF system is generally used for near-wellbore (NWB) applications or for fracture isolations. Average particle size ranges from 5 to 10 µm, which prevents significant penetration into the formation matrix. Other important characteristics of the RSF system are that it is 100% acid soluble and exhibits no shrinkage after setting; in fact, testing has shown that the system slightly expands after setting.
Several case histories are presented to illustrate the application of this innovative system, including (1) controlling severe circulation losses while drilling, (2) permanently or temporarily (depending on the application) shutting off water and gas producing zones, (3) formation consolidation, (4) and setting annular plugs in the wellbore (cased hole and openhole completions in vertical, deviated, and horizontal wells), among others. A variety of case histories are presented from varying types of reservoir and wellbore completions, along with lessons learned after more than 500 well interventions using this system.