Project Case Study: Online Sand Removal System for Water Tanks

Abstract

Abstract The Elk Hills and Buena Vista Field, located in the southwest San Joaquin Valley, have over 3000 active wells producing from various reservoirs which are predominantly characterized by a deep marine siliceous shale, or sandstone lithology and are overlain by a shallow marine, tidal-influenced sandstone lithology. Wells are completed as slotted liner, gravel pack, case and perforation, with some wells hydraulically fractured or acid stimulated, producing between 0 and 4000 barrels of liquid per day and 0 to over 1 million standard cubic feet of gas per day. With the variety of reservoirs, and fluid compositions, produced solids and scales accumulate in the surface facility equipment, limiting capacity of vessels, tanks, overall fluid handling capacity and water quality. Dehydration facilities and water treatment facilities experience frequent buildup of sand and scales in the water tanks negatively affecting separation performance and increasing maintenance costs related to tank cleanouts and pump repairs. Excess solids also impact water injectivity and subsurface performance. California Resources Corp (CRC) reviewed options for reducing operating costs, maintenance downtime, and risks from human exposure during maintenance and chose to implement an online sand removal system based on vortex fluidizer technology. This paper discusses implementation of the project and will review major considerations and important decisions made during project design and implementation. The paper will highlight case studies from the literature supporting a decision to select flexible HDPE in lieu of stainless steel and carbon steel for both internal and external slurry lines as a cost saving measure. Special considerations for design of slurry piping and pumping systems will be addressed.