Penentuan Karakteristik Fluida dan Estimasi Temperatur Reservoir Panas Bumi di Sekitar Gunung Talang

Abstract

Telah dilakukan penelitian penentuan karakteristik fluida dan estimasi temperatur reservoir panas bumi di sekitar Gunung Talang sebagai salah satu tahap awal penentuan pengembangan sistem panas bumi di Kabupaten Solok, Sumatera Barat. Penelitian mengambil sampel 12 titik mata air panas sebanyak 100 ml di sekitar Gunung Talang. Penentuan karakteristik fluida panas bumi dilakukan menggunakan diagram segitiga Na-K-Mg dan Cl-Li-B. Diagram Na-K-Mg digunakan untuk menentukan keseimbangan fluida reservoir panas bumi. Diagram segitiga Cl-Li-B digunakan untuk menentukan asal-usul, pendidihan, dan pengenceran fluida reservoir panas bumi. Estimasi temperatur reservoir dilakukan dengan persamaan geotermometer. Pengukuran unsur Na, K, dan Mg dilakukan dengan alat Atomic Absorption Spectroscopy (AAS). Pengukuran unsur Li, B dan Ca dilakukan dengan alat Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) dan pengukuran senyawa SiO2 dengan alat Visible Spectroscopy. Pengukuran unsur Cl dengan metode titrasi asam basa. Hasil penelitian menunjukkan bahwa semua mata air panas bumi di sekitar Gunung Talang berada pada immature water yang menandakan fluida reservoir panas bumi telah mengalami pengenceran dengan unsur lain. Fluida reservoir berasal dari sistem hidrotermal baru yang dipengaruhi oleh magma Gunung Talang. Sistem panas bumi di sekitar Gunung Talang didominasi air dan mata air panas keluar pada zona outflow. Pendidihan fluida reservoir panas bumi berada di bawah permukaan bumi hingga kedalaman sekitar 150 meter. Estimasi temperatur reservoir panas bumi dengan geotermometer silika adalah 147,63 oC - 179,77 oC, yang termasuk dalam sistem panas bumi bertemperatur sedang.Kata kunci : diagram segitiga, Gunung Talang, reservoir panas bumi.

Identification of Fault Structure in the Vicinity of Bukik Gadang Hot Spring Mount Talang Subdistrict Using Geomagnetic Method

“…One of the areas in Mount Talang that has geothermal prospects is Nagari Sungai Janiah, Gunung Talang District. This potential is evidenced by the presence of surface manifestations in the form of Bukit Gadang hot springs with a surface temperature of 43.1°C and a pH of 8.2 (Utami & Putra, 2018). In this region, it is also found hot springs, steaming ground, hydrothermal eruption, and alteration rocks, as well as the results of previous investigations showing the existence of a geothermal system in the area (Munandar et al, 2003).…”

“…The peak of this reservoir is at a depth of about 1800 m and deepens towards the north which can reach a depth of about 2500 m (Kholid & Marpaung, 2011). Research related to fluid characteristics and reservoir temperature estimation by Utami and Putra (2018) around Mount Talang shows that the fluid is in immature water indicating that the geothermal reservoir fluid has been diluted with other elements. The reservoir fluid comes from a new hydrothermal system influenced by the magma of Mount Talang.…”

“…The reservoir fluid comes from a new hydrothermal system influenced by the magma of Mount Talang. The estimated temperature of the geothermal reservoir using a silica geothermometer is 147 o C -179 o C, which is included in the mediumtemperature geothermal system (Utami & Putra, 2018).…”

Numerical Modelling of Geothermal Reservoir in Gunung Talang, West Sumatera, Indonesia

“…(Source: Pusat Sumber Daya Geologi, 2013) springs around Gunung Talang, which are categorized as immature water, indicate that the geothermal reservoir fluids have been diluted with other elements (Utami and Putra, 2018). These reservoir fluids derived from the new hydrothermal system that influenced by Gunung Talang magma.…”

“…These reservoir fluids derived from the new hydrothermal system that influenced by Gunung Talang magma. The boiling geothermal reservoir fluid is located below the subsurface at 150 m depth approximately (Utami and Putra, 2018).…”