Controlling Formation Fines at Their Sources To Maintain Well Productivity

Abstract

Summary Migration of formation fines has been shown to cause production decline in many wells. Despite the availability of new downhole tools for use in well stimulation and completion, the ability to sustain desired production levels is often plagued with fines migration problems. The solution to this problem is appropriate treatment to mitigate fines migration at its source. This paper describes the use of an ultra-thin tackifying agent (UTTA) for stabilizing fines in high-rate producing or injection wells. This UTTA is applied as part of an initial prepad in fracturing or gravel-packing operations, as a remedial treatment, or as a post-treatment following acid fracturing or matrix acidizing treatments. The primary purpose of UTTA application is to immobilize formation fines so that they will not detach, migrate with flowing fluids, plug the pore channels, and reduce the flow path permeability. Results of laboratory testing indicate that the UTTA system is applicable to most types of formation fines, including coals, sandstones, and carbonates. Once injected into the formation matrix or proppant pack, the UTTA forms a thin film on formation surfaces, encapsulating the fines. Capillary action helps pull the tackifier into the contact points, fixing the particulate in place without plugging the pore throat. The UTTA does not require a shut-in time after its application. The thin film tackifier does not harden, but remains flexible, enhancing the ability of a formation to withstand stress cycling and allowing the formation to handle high shear stress during high flow rates. Introduction Hibbeler et al. (2003) provide an excellent review of fines migration mechanisms. Many investigators have examined factors affecting permeability decline because of fines migration and clay swelling, including salinity changes, pH, and flow rate (Muecke 1979; Gruesbeck and Collins 1982). Migration of formation fines is known to cause severe formation damage during production, limiting the potential production of the well. Various techniques have been developed in the industry over the years as fines-stabilizing solutions to overcome the effects of fines migration (Muecke 1979; Sharma and Sharma 1994). Acidizing has often been used to dissolve fines by "unblocking" and enlarging pore-throat geometry in the formation near the wellbore to increase the permeability of the formation. Production performance in wells that have been acidized or acid-fractured has often been disappointing. High production rates typically last only a short time, followed by a drastic drop in production because of the damage caused by fines plugging. Other chemical treatments, such as the inclusion of clay-stabilizing surfactants as part of the completion fluids, or polymers in remedial operations, have been applied in an effort to minimize fines migration and enhance well productivity (Kalfayan and Watkins 1990; McLaughlin and Weaver 1982; McLaughlin et al. 1976). These treatments commonly require that the treatment fluids be injected deep into the formation matrix, allowing the surfaces of the fines and pores to contact and interact with the treating fluid. Large volumes of treating fluid are often required to achieve the desired results. Most such treatment fluids provide only temporary solutions because they tend to desorb with time and with the production of fluids from the well.

Fines Migration: Problems and Treatments

“…Once pH value increases dramatically, it will dissolve silica cement to cause more fines and the result can be fines migration [29,30]. The sources for increase of pH value can be from injected mud filtrates, cements or work over fluids or from decrease salinity of in-situ fluids.…”

Analytical Evaluation of Nanoparticle Application To Mitigate Fines Migration in Porous Media

“…Meanwhile, a genuine shock occurs to maintain the physical integrity of analytical solutions that can be determined by Eqs. 33 and 34 (Noh et al 2007;Moghanloo and Lake 2010;Moghanloo 2012aMoghanloo , 2012b. In this paper, this shock front represents the "nanoparticle-absorption front" that connects the constant-state region and the initial-condition region, as shown in Fig.…”

Clay Migration in Proppant during Production in Argillaceous Unconsolidated Reservoir

“…Section 5 concludes the paper. The experimental apparatus used in this paper are mainly based on a modified API standard fracture conductivity instrument [8,9] that consists of an Automated hydraulic intensifier system, a fluid injection system, and a hastelloy conductivity cell (Figure 2). This instrument can simulate real reservoir conditions.…”