Optimization of the Distribution of Drilling Boreholes in Methane Production from Coal Seams

Anna Wątor,Jarosław Chećko,Tomasz Urych

doi:10.46873/2300-3960.1024

Abstract

The paper presents an evaluation of methane production from coal seams. The Warszowice-PawłowicePółnoc deposit was selected for numerical modelling of methane production. The numerical model was made for a fragment of this deposit of about 2 km2. The numerical model was constructed for 6 seams. Three deposits were selected for simulation of methane production. Three horizontal boreholes were designed within the model area, referring to the existing Suszec-19 borehole. A number of simulations related to methane production from the selected deposits were performed. They included different variants of the number of boreholes and also took into account the z-pinnate method. The analyses proved that the most advantageous is the production of 3 directional boreholes simultaneously with the z-pinnate method. For this variant the degree of methane production was 21.9% of the estimated resources.

Highlights

The global development of the economy requires an increase in electricity consumption, which leads to a continuous increase in demand for electricity
The problem of methane presence in coal beds has been dealt with for many years [3e6], including laboratory tests related to this issue [7e9]. It has inherently been a threat occurring during exploitation of coal seams
The methane production processes from coal deposits have been estimated on the basis of an ECLIPSE simulator with Coal Bed Methane option, which has defined mechanisms responsible for the flow of gases and water in the coal beds (desorption of gas from the coal matrix into the fracture system, diffusion into the matrix according to Fick's law and Extended Langmuir isotherm is identical to the usual Langmuir isotherm giving the storage capacity as a function of pressure only (4): ÀÁ Lp

Summary

Introduction

The global development of the economy requires an increase in electricity consumption, which leads to a continuous increase in demand for electricity. In Poland, the primary source of energy is mainly hard coal and lignite. The use of these fuels causes large environmental pollution, which has an impact on global climate warming. In Poland, methane occurs mainly in gas deposits (conventional) and in coal seams (unconventional) in hard coal deposits (CBM e coal bed methane) [1]. The problem of methane presence in coal beds has been dealt with for many years [3e6], including laboratory tests related to this issue [7e9]. It has inherently been a threat occurring during exploitation of coal seams. It is believed that in coal with a low degree of carbonization, methane is formed as a result of micro organism’s presence, while in coal with a higher degree of carbonization as a result of thermal processes of organic matter [2]

Methods

Results

Conclusion