Controlling Solids Flowback to Maintain Production of Hydrocarbons: A Review of Successful Chemical Technologies in the Last Decade

Abstract

TX 75083-3836, U.S.A., fax +1-972-952-9435. AbstractBillions of dollars are lost each year as a direct or indirect result of unwanted solids flowback with the production of hydrocarbons. These solids, whether formation sand, fines, or proppant produced from propped fractures, restrict well production by plugging sand screens, perforation plugging or collapse, or wellbore fill. They often cause damages to downhole and surface equipment and storage facilities. Workovers and shutdown time of the well contribute considerably to the frequent and costly cycle in solving, or at least managing, the solids-production problems. Often, the solids production becomes intolerable, especially in offshore environments.Numerous studies have been performed to identify the mechanisms and causes of solids production. Both mechanical and chemical solutions have been applied to limit or to overcome the problems. This paper presents a detailed review of chemical technologies that have been successfully used for controlling solids production in the last decade, either as part of a primary completion or a post-completion treatment solution. It provides insight to the strategies of how these chemical systems were optimized to stabilize and inhibit the movement of the particulates at their sources, either inside formation matrix, in a gravel pack, or in a proppant pack placed during a frac-pack or other fracture-stimulation treatment. Case histories are provided to support the obtained benefits and advantages. A future direction of chemical technologies for solids-flowback control is also discussed. IPTC 13725From treating proppant in frac-pack treatments of soft formations to hydraulic-fracturing treatments in the tight rocks, chemical-coating systems have shown they improve and maintain well production by protecting proppant packs and mitigating migration and/or production of solids. Production of SolidsThe oil and gas industry has been consistently looking for ways to alleviate the problems arising from the flow of solids from the formation or fracture. The solids-production problem can be classified into two main categories:• Proppant flowback.• Formation-sand and fines production. Proppant FlowbackThe production rates of many fracture-stimulated wells in the world today are curtailed because of sustained proppantflowback problems. As proppant produces out of the fractures along with the produced fluids, fracture conductivity diminishes with time and closure stress as the fracture width decreases, thereby creating a choking effect that causes the potential production of the well to decline. If the produced proppant remains in the wellbore, it can cover the perforation interval, limiting the production flow path into the wellbore. This process might require a well cleanup to remove the unwanted proppant from the wellbore to re-establish the production from the entire perforated interval.If the proppant flows back to the surface, it can potentially cause severe damage downhole (e.g., to bottomhole rod pumps or electrical submersible pump...