Solids production and control in petroleum recovery

Reservoir solids may be produced during exploitation of petroleum reservoirs. Solids management practices depend on the nature of the reservoir and the produced fluids. For conventional oil and gas reservoirs, operators normally have focused on prevention or control of solids influx into production wells. In Canada, exploitation of heavy oil reservoirs has been found to be more effective when solids are produced. Solids production from conventional oil and gas reservoirs can have detrimental effects on well productivity and equipment. Therefore, the practice has been to attempt to prevent or control solids influx into the wells by using screens, gravel packs, or other means to restrict solids flow. If, when, where, and how to install solids control systems are governed by both cost and risk factors. From a solids management point of view, production of heavy oil from unconsolidated formations poses different challenges than conventional oil and gas production. Production of large quantities of solids is critical for maintaining the productivity of wells in heavy oil reservoirs. This has necessitated the development of special pumping systems to transport fluids with high solids content. Many reservoirs are now being exploited by horizontal wells, which have long horizontal contact with the reservoir. Solidsmore » control methods for horizontal wells have been adapted from those used in vertical wells. Special techniques and equipment have been developed to remove deposited solids from horizontal wells. Specially designed equipment and techniques are required for the surface handling of high solids cut fluids. Separation, cleaning, and disposal of produced solids can be costly, especially if the solids must be oil-free to satisfy environmental regulations. 138 refs., 20 figs., 3 tabs.« less