| Title | PRECIPITATED CALCIUM CARBONATE AS A SUSTAIANBLE ALTERNATIVE TO CEMENT IN GEOTHERMAL WELL CEMENTING |
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| Authors | Anjan Koirala, Mahesh Acharya Jared Cantrell Trevor Atkinson Mustafa Mashal |
| Year | 2026 |
| Conference | World Geothermal Congress |
| Keywords | |
| Abstract | This proposed research explores the feasibility of utilizing Precipitated Calcium Carbonate (PCC), a by-product of sugar beet industry, as a sustainable and economically viable alternative to Ordinary Portland Cement (OPC) for geothermal well cementing applications. Cementing and casing operations account for approximately 30–40% of total geothermal well construction expenses. Through the successful replacement of a portion of OPC with PCC, this study aims to develop high-performance, cost-effective cement blends tailored for the highly intensive geothermal environment. The first phase consists of PCC being incorporated into concrete as a partial replacement of cement, at 5%, 10%, 15%, 20%, and 25% increments by weight. Compression and tensile strength tests was conducted. The benchmark mix with 0% PCC replacement achieved compressive and tensile strengths of 4540 psi (31.3 MPa) and 427 (2.9 MPa) psi, respectively. Incorporating 5% PCC enhanced the mechanical performance, increasing compressive strength by 9.47% to 4970 psi (34.3 MPa), and tensile strength by 2.93 % to 439 psi (3 MPa). However, further increments of PCC led to a reduction in both compressive and tensile strength. The second phase involved thermal cycling of optimized concrete mixes (0%, 5% and 10% PCC replacement) to simulate geothermal well conditions. Specimens underwent repeated heating up to 250°C and cooling to 10°C in an oven to evaluate their durability and performance under highly intensive geothermal environment. This study’s findings are expected to provide valuable insights into enhancing structural integrity of geothermal wells while significantly lowering cementing costs and promoting sustainable practices in geothermal energy development. |