Evaluasi Pendahuluan Potensi Underground Coal Gasification Di Cekungan Sumatra Selatan: Studi Kasus Batubara Formasi Muara Enim

Abstract

Salah satu cara memanfaatkan batubara bawah permukaan adalah dengan cara mengonversinya ke dalam bentuk gas yang lebih ramah lingkungan melalui metode underground coal gasification (UCG). Cekungan Sumatra Selatan adalah salah satu cekungan batubara produkfif di Indonesia. Kegiatan evaluasi ini bertujuan untuk untuk mengetahui lokasi potensi batubara yang cocok untuk pengembangan UCG. Evaluasi potensi batubara Indonesia untuk pengembangan UCG di cekungan ini, dilakukan dengan cara mengarakterisasi lapisan batubaranya. Batubara cekungan Sumatra Selatan di Daerah Bayung Lencir, Muara Kilis, dan Srijaya Makmur dievaluasi karakteristiknya untuk melihat potensi UCG pada batubara tersebut. Parameter karakteristik yang dievaluasi meliputi peringkat, ketebalan, kemiringan dan kedalaman lapisan batubara, rasio kedalaman dan ketebalan lapisan batubara, batuan pengapit berikut ketebalannya, kondisi hidrogeologis (posisi batubara terhadap akuifer), struktur geologi serta sumber daya batubara. Hasil evaluasi menunjukkan, berdasarkan karakteristik batubaranya, daerah Bayung lencir merupakan daerah yang cocok untuk pengembangan UCG.

Implementing the Calculations and Characterization of Underground Coal Gasification using Data Analytic Method

“…Site selection is something very important in the UCG analysis by considering the thickness and depth of the coal seam, coal rank and other properties [7], roof and floor rock, structural geology of the area, calorific value, depth to thickness ratio, and the dip angle of the seam itself. Our study refers to Dwitama et al (2021) [8] which summarized the UCG criteria as shown in Table 2. The UCG technology will convert the solid coal into gas in situ by injecting air or oxygen.…”

“…The UCG technology will convert the solid coal into gas in situ by injecting air or oxygen. This injection will ignite the coal and flows in the targeted coal seam or surrounding rocks that increase temperature, pressure, and gas content as the oxygen is continuously injected and let the high-pressure gas ascend along the borehole which is known as the gasification process [7][8][9][10]. This gasification process can be optimal if we gasify the low-rank coal as it will assist in the reduction of carbon emissions due to the chemical and physical transformation [9,[11][12][13].…”

“…Another sorting that we need to do for finding the UCG prospecting seam is considering the thickness of the coal seam itself. We put the threshold value in the computation system according to several studies that have been done and summarized in Dwitama et al (2021) [8]. For lignite rank coal, the thickness of the coal should be 3.5 meters.…”

“…Once the system finds the permeability zone (layer), the system will stop to sum in as we do not need it. According to Dwitama et al (2021) [8], we used the minimum thickness of both layers to be twice the thickness of the coal for the roof and once the thickness of the coal for the floor.…”

“…However, there is still some characterization that might be possible to be put into the coding system. Dwitama et al (2021) [8] reviewed the good dip in selected seam for developing the UCG are determined in less than 65˚ according to some successful projects around the world. The coal resources are still considered for the UCG development.…”