Preparation of a Synthetic Geo-Polymer Based LCM Utilizing Saudi Arabian Volcanic Ash for a Sustainable Development: Method, Lab Testing and Applications

Abstract

Abstract We successfully developed a novel geo-polymer based LCM to treat moderate to severe losses. Geopolymers can be prepared utilizing waste materials such as fly ash. In Saudi Arabia, we have enough volcanic ash to sustain the development of the geo-polymer based LCM. This novel LCM was prepared by utilizing a Saudi Arabian volcanic ash. The volcanic ash particles were activated with an alkali solution to undergo a geo-polymerization reaction. The geo-polymerization was designed to delay and successfully controlled to gel up and form the target geo-polymer barrier after the fluid goes inside the wellbore. This is very important to avoid an early setting of the fluid. The objective of this paper is to discuss the formulation and preparation of the geopolymer barrier as a lost circulation material. Also, to investigate the effect of both the addition amounts and concentration of the activating solution on the final geopolymer physical properties as well as to detail lab testing. Saudi Arabian volcanic ash particles were activated by a mixture of NaOH, sodium silicate and water to develop a geopolymer barrier. In this study, we prepared four different activating solutions by varying the alkali concertation and the addition amounts based on the volcanic ash chemical composition. The effect of these variations on the geo-polymerization in terms of setting time and rheological properties of the final geopolymer barrier were investigated. This was done to develop a geo-polymer barrier with a delayed and controlled setting to assure a right placement inside the wellbore. In addition, the chemical conditions were evaluated to simulate a variety of downhole conditions to prove the effectiveness of this novel geo-polymer composition as an LCM to treat moderate to severe losses. The lab testing includes thickening time, rheology, compressive strength and a chemical analysis of the Saudi Arabian volcanic ash. We found that thickening time and rheological properties of the final geo-polymer barrier are strongly affected by the alkali concentration and the addition amounts of the activating solution. This novel geo-polymer barrier can remain in a liquid phase from a few minutes to several hours based on the desired conditions. The final and target geo-polymer barrier will appear and gel as a solid thereby preventing loss circulation.