Reverse Circulation Cementing of Geothermal Wells: A Comparison of Methods

Abstract

Reverse circulation cementing has been used for a number of years to cement casing in geothermal wells. There are several methods of reverse circulation cementing, all of which send cement down the annulus from surface to the casing shoe. The four most commonly used will be discussed. All of these methods significantly reduce the circulating bottom hole pressure (BHP). Reducing this pressure reduces the risk of loss of circulation while cementing, eliminating the need for costly and time-consuming secondary cement jobs. Each technique presents different challenges and influences both the circulating BHP and risk of lost circulation while cementing. The purpose of this paper is to review four commonly used reverse circulation cementing techniques and challenge cementing companies to develop standards to model circulating BHP. Having standardized BHP models will allow for more informed decision-making when it comes to choosing between conventional and reverse circulation cementing techniques. The following topics will be explored: reverse circulation advantages, rheology for conventional and foamed cement, reverse cementing into the shoe, reverse cementing to surface through drill pipe, and displacement options.