Abstract
This paper describes the evaluation and field application of a proppant-consolidation system [as aresin-coated proppant(RCP) is otherwise known] that was developed for treating high-temperature wells (i.e., ≥175°F). Proppant treated with the new high-temperature liquid coating will be called HTL-RCP for the purposes of this paper. The HTL-RCP system is unique in that it is a single-liquid treatment that is used to coat proppants on-the-fly during a treatment on location without the need for specialized metering equipment. The coating promotes adhesion between proppant grains to such an extent that even if the well is flowed back immediately after a treatment, it still cures to give a high-strength consolidation. This paper presents the results of field tests, the evaluation of treatments for proppant-flowback control in tight formations, the application of screenless completions in high-permeability formations, consolidation tests, and breaker-compatibility studies, all of which were conducted under simulated treatment and downhole conditions. The paper describes the development of rock-mechanical testing that was performed to help the prediction of long-term consolidation properties under production conditions of closure stress, cycling, and high bottomhole temperatures (BHTs).
Testing under simulated treatment and downhole conditions indicates that unlike other proppants that are precoated with phenolic resins (P-RCPs), consolidations using the HTL-RCP system do not lose strengths with extended onsets of formation closures. In addition, strengths several times those obtained with other RCPs (using the same amounts of resin) are produced. Rock-mechanical testing indicates that the material is very resistant to cycling and creep. A Mohr-Coulomb failure envelope obtained by rock-mechanical tests indicates that consolidations exceeding strengths required for screenless completions are obtainable under downhole conditions with the material. Treatment with the material does not require additional breaker, resulting in controlled fluid breaks and good cleanup without complicating the fracturing treatment. Effective proppant-flowback control and enhanced productivity were observed in all of the wells treated with the HTL-RCP system.
