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Jharkhand
The Indian government has signed contracts for 31 discovered small fields under the third round of bidding, and for four coalbed methane (CBM) blocks under the fifth round of bidding with 14 domestic companies. These blocks have been awarded. Among these blocks, the Oil and Natural Gas Corporation (ONGC) has signed six contracts for discovered small fields, with three each for fields in the Arabian Sea and Bay of Bengal. These include four contract areas as sole bidder and two contract areas in partnership with Indian Oil Corporation Ltd. The ONGC has also signed two contracts for CBM fields situated in Jharkhand and Madhya Pradesh.
Country:
- Asia > India > Madhya Pradesh (0.30)
- Asia > India > Jharkhand (0.30)
Industry:
- Government > Regional Government > Asia Government > India Government (1.00)
- Energy > Oil & Gas (1.00)
SPE Disciplines: Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Coal seam gas (1.00)
ABSTRACT: Increase in subsurface temperature causes changes in physical & mechanical properties of rocks thereby causing instability in the strata which results in rock failure & surface subsidence. In this study, sandstone rock samples were collected from the Damodar River Valley of Dhanbad, India and have been subjected to laboratory experiments to evaluate the temperature effects on sandstone rock. Individual rock samples were given a heat treatment at a specified temperature. The temperature range of 200degC to 1200 degC is considered with the upper limit following the highest reported temperatures in the region. Under this heat treatment, the sandstone samples were first heated at a specified temperature for continuous 6 hours a day and 7 days. After this process, their physical properties (mineralogy, grain size and spontaneous imbibition by water and mechanical properties (Uniaxial compressive strength-UCS, tensile strength, ultrasonic wave velocities etc.) were determined in the laboratory. The result obtained shows that the temperature has a significant effect on the measured rock properties an attempt has been made to explain these changes using thin-section analysis. For example, the trend observed on UCS versus temperature crossplot suggest an increase in strength up to 400DegC and then decrease upto 1200 DegC. The initial increasing trend is attributed to the removal of moisture and change in compactness whereas the decreasing UCS trend is the result of the development of multiple fractures. These fractures enhance the secondary porosity and are evident in the thin sections heated to 600 degC,800 degC,1000 degC and 1200 degC. Because of the changes at the granular level, most of the physical and mechanical properties of the sandstone rock are influenced.
coefficient, core sample, correlation, DegC, determination 0, fracture, hardness, mechanical properties, porosity, Protodyakonov, quartz grain, reduction, Reservoir Characterization, reservoir geomechanics, rock sample, spontaneous imbibition, strength, temperature range, tensile strength, Upstream Oil & Gas, variation, Wellbore Design
SPE Disciplines:
Abstract The paper deals with geotechnical study for the final slope of 140m high final open pit mine slope at SE Block of West Bokaro Collieries, Tata Steel. It is mainly characterized by sandstone and coal. The bulk density and direct shear tests were conducted at Rock Mechanics Laboratory of CIMFR on the samples collected from the field. The geotechnical mapping was done on the exposed benches of the quarry as per the norms of International Society of Rock Mechanics (ISRM 1978). The kinematic analysis was done to determine the critical orientation of structural discontinuities. After identifying kinematically possible failure modes, detailed slope stability analysis was carried out by GALENA software based on limit equilibrium method. The present study reveals that the 140m high final slope could be designed with 47 degree overall slope angle. The sensitivity analysis shows that the influence of water is also alarming. It was recommended that the slope should be kept in drained geomining condition by providing suitable drainage and keeping drainage effectively maintained. 1 Introduction The geotechnical study was conducted for optimum slope design of final highwall at SE Quarry, West Bokaro. The Quarry-SE is situated in Jharkhand state and is owned by M/s. Tata Steel Ltd. The rock discontinuities were mapped at the exposed benches of the pit as per the norms of International Society of Rock Mechanics (ISRM 1978). Geotechnical mapping was undertaken to determine the critical orientation of structural discontinuities. After identifying kinematically possible failure modes, detailed slope stability analysis is carried out by limit equilibrium method. Sensitivity analysis was done to determine the most effective remedial measure for any critical slope. 2 Geology and Geohydrology The slopes of the quarry are mainly characterized by Overburden sandstone and coal. The sandstone is well jointed. The average annual rainfall is around 1400 mm. The eastern part of the pit has been fully developed. The groundwater condition in drained geomining condition of the final highwall slope was considered to be with 30m water table from the pit bottom. It was considered based on field observations, engineering judgment and previous experiences in this type of geomining condition in adjacent mines. The most likely geo-mining condition for the quarry would be drained condition. The undrained geomining condition was simulated by the presence 75m water table from the pit bottom. This condition was considered to arise when the mine management does not implement the remedial measures related with the drainage in totality.
detailed slope stability analysis, discontinuity, drainage, final highwall slope, geo-mining condition, highwall slope, kinematically possible failure mode, metals & mining, quarry, rainwater, Reservoir Characterization, reservoir geomechanics, rock mass, Rock mechanics, slope angle, slope face, slope stability, stability analysis, Upstream Oil & Gas, West Bokaro Colliery
SPE Disciplines: Reservoir Description and Dynamics > Reservoir Characterization > Reservoir geomechanics (0.77)
Abstract: This paper describes the findings of a numerical modelling based case study to assess the feasibility for extraction of pillars with controlled subsidence of the sur-face in Mahuda Top seam III at Murlidih Bord and pillar mine under Jharia coalfield India. Controlled subsidence on the surface was required to avoid any adverse impact of mining induced subsidence on built-up area at the surface structures. Two dimen-sional numerical modelling has been done to quantify the various parameters associat-ed with mining induced subsidence. The stability of barrier pillar has also been evalu-ated to confirm the validity of controlled extraction width for limiting damage on the surface. Based on findings of the study, the feasibility of extraction of the proposed panels has been assessed. The results of the study have been very helpful in planning the layout of Bord and Pillar mining panels to meet the site specific objecttives with higher recovery of coal from the underground workings. 1 INTRODUCTION Coal reserve in any country is limited. Therefore, every scientific effort must be made to extract the seams as completely as practicable. Apart from these strategic and lim-ited reserve reasons, there are significant economic and operational reasons that favour total seam extraction. The trend towards increasing emphasis on higher recovery of coal seams has also been clearly evident from the changes in mining methods that have taken place after nationalisation of the coal mining industry in India. However, a major feature associated with such methods is that, the mining induced ground move-ments associated with such mining system changes the surface topography and intro-duce significant strain in the subsurface. As mining companies operate under regulations, they are essentially required to obtain permission or have negotiation for the right to subside any property (Bauer 2008).
coal seam, eurock 2012, extraction, feasibility study, knowledge management, Maximum Subsidence, metals & mining, numerical modelling, panel 29, Panel PX, pillar, Reservoir Characterization, reservoir geomechanics, rib pillar, strata, subsidence, subsidence slope, surface strain, surface subsidence, Thickness, virgin panel px
SPE Disciplines:
CBM Prediction: A Case Study of Field Scale Development in Bokaro Basin, India
Roy, Kalyan Kumar (Oil and Natural Gas Corporation Limited Institute of Reservoir Studies, ONGC, Ahmedabad-380005, India) | Parulkar, S N (Oil and Natural Gas Corporation Limited Institute of Reservoir Studies, ONGC, Ahmedabad-380005, India)
Abstract CBM is likely to address in a limited way the world's growing energy needs. In India the epicenter of such a process is geographically active in the east, predominantly known for conventional coal mining. Devoid of any known natural gas resource, the area though conducive for CBM production, commercial prediction needs utmost care and caution, as supply commitment is never equipped with fall back option. The geological model thus for Barakar Formation of Bokaro Field is defined with reasonable confidence for three potential CBM seams assessed through 3 vertical wells with a deliverability 10,000 m3/d for the first tested well. Proven CBM potential volumes estimated thus needs to be translated into a way forward programme of monetization firmed up through simulation based profile. A comprehensive full field dual porosity/permeability simulation model, incorporating Langmuir isotherm and GC data generated across the geographical spread is built to understand the process intricacy. Effort to history match the initial Qw with time in all CBM simulation as a depressurization event is a difficult proposition as interruption in Qw, coupled with Wp bookkeeping are often very subjective. However, permeability/volume modifiers within acceptable limits led to replicating near history of Qg and Gp. The prediction was QC'd on single well forecasting basis through other commercial software, and the profiles though identical was in substantial variation in gas breakthrough timing, the possible reasons identified as a learning for the future. Field scale development with an optimized variant of 38 vertical wells at 60 acres well spacing envisages peak Qg of 1.3 LCMD and RF being 32% after 15 years. The criticality is however well scheduling designed to cater to the industry needs of a reasonable plateau period. This paper assimilates the lessons learnt from the applications of simulation to be used for devising field scale CBM development strategy and is suggestive of the Do's and Don'ts of initial data generation and lists caution in the prediction specially the depressurization process, well spacing criteria, drilling schedule for plateau generation.
asset and portfolio management, bokaro basin, case study, cbm prediction, cbm simulation, coal bed methane, coal seam gas, coalbed methane, complex reservoir, fall back option, field scale development, flow in porous media, Fluid Dynamics, geographical spread, history matching, Modeling & Simulation, Petroleum Engineer, prediction, production control, production monitoring, Reservoir Characterization, reservoir simulation, Reservoir Surveillance, seam, Thickness, Upstream Oil & Gas, variant, volatile bituminous, well wb
SPE Disciplines:
Abstract Combating climate change by mitigation of release of the anthropogenic greenhouse gases has attracted worldwide attention towards research and policy formulations. One such approach utilizes the geological sequestration of carbon dioxide into coal beds which is a value addition process, capable of enhancing the yield of coalbed methane (CBM) in producing reservoirs. CO2 is preferentially adsorbed onto the microporous structure of coal seams and it displaces the methane molecule from the adsorption sites, thereby enhancing the production of the low carbon eco-friendly fuel. In this study, a finite difference based reservoir simulator, COMET3, has been utilized for construction of underground coal bed scenario for Indian seams. Numerical modeling involves solving complex equations used to describe some physical process by iterative approximate solutions. Such simulation is worked out for underground coal of Lower Gondwana sequence in Jharkhand state in India. Detailed field work was carried out to collect samples and field data. Laboratory tested parameters and some from published data were utilized for construction of the numerical model. The best fit model was developed for estimation of the volumes of gases involved in CO2 enhanced coalbed methane recovery. It also gives a detailed analysis of distribution of gases with time and space. The results obtained from the simulation are quite encouraging and ascertain that the process of CO2 enhanced CBM recovery seems to be technically feasible for Indian scenario also. The simulation was executed for a period of 20 years to understand the space-time disposition of injected CO2 and recovery of methane from the reservoirs. It is quantified in this study that for the chosen dimensions of coal block, a total of 15.1 bcf of CO2 can be injected into the reservoir and approximately 5.0 bcf of methane can be recovered.
basin, carbon dioxide, Carbon Management Technology Conference, climate change, cmtc 151614, co 2, coal bed methane, coal seam gas, coalbed methane, complex reservoir, emission, India, indian subcontinent, injection, international journal, metals & mining, recovery, Sequestration, storage, Upstream Oil & Gas
Country:
- North America > United States (0.95)
- Asia > India > Jharkhand (0.34)
- North America > Canada > Alberta (0.29)
Oilfield Places:
- Asia > India > Tripura > Assam-Arakan Basin (0.99)
- Asia > India > Tamil Nadu > Bay of Bengal > Cauvery Basin (0.99)
- Asia > India > Rajasthan > Rajasthan Basin > Bikaner Nagaur Basin (0.99)
- (4 more...)
SPE Disciplines:
Abstract Fracture systems comprise the primary flow path within coal bed methane (CBM) reservoirs. These fractures, also called as cleats, define the reservoir character and fluid flow potential. Cleats are commonly mutually orthogonal and occur perpendicular or at very high angles to the bedding. The standard suites of logs, such as density/neutron, gamma ray and resistivity, define some of the petrophysical properties of the coal layers, but the nature and extent of cleating often remains poorly defined from these logs and by using standard log evaluation methods. A CBM well may often penetrate multiple reservoir zones (seams) and properly characterizing the cleats will help in determining which of these seams should be completed to optimize the production. In addition, through better seam characterization, a technical basis for a preferred completion method (horizontal well, hydraulic fracture, open hole or cavity) can be ascertained. High cleat density in coal seams is an essential requirement for better fluid flow in CBM reservoirs. The primary cleat direction and its relation with the in-situ horizontal stress directions define the fluid flow potential through the cleats and such information can be used to select the completion method. In this study, full waveform sonic log with monopole and flexural waveform and high resolution electrical image log data from CBM wells in Jharkhand, India, have been integrated, in a bid to identify the ideal candidates for completion. Coal seams for best production potential are identified through cleat density characterization. In this paper, we show how compressional and shear slowness variation and Stoneley waveform transmission coefficient analysis are used to interpret the variation in cleat density. The cleat density is further validated from the fracture analysis using micro-resistivity image logs. Cleat orientation can be determined from the detailed structural evaluation of the fractures seen in the high resolution resistivity image. Maximum horizontal stress direction has been computed from acoustic anisotropy evaluation. This maximum stress direction and cleat orientation have been integrated to identify seams that will have better deliverability of fluids. In this paper we provide a guideline for selecting a completion methodology in coal bed methane wells based on cleat density, stress direction, cleat orientation and wellbore stability. Introduction CBM reservoirs have dual permeability system, characterized by low permeability matrix part connected by high permeability orthogonal and sub vertical fractures (with respect to bedding) called cleats. The extended, continuous fractures are termed as face cleats and subsidiary shorter length fractures are classified as butt cleats. As a result of geometry and connectivity variation, significant face and butt cleat permeability anisotropy is prevalent in coal seams ((McCulloh et al. 1974, Mavor at al., 1991,). Figure 1 displays a schematic of cleat network in a coal bed. The permeability of the cleat system is a reservoir property of primary importance because commercial levels of production cannot be obtained unless a well-developed natural fracture system is in communication with the wellbore (Mavor et. al. 1994) The degrees of cleating, nature of cleat network and relative connectivity of the cleat system varies from one coal seam to those of the other and have a significant bearing in their production characteristics even in the commingled production scenario.
SPE Disciplines: Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Coal seam gas (1.00)
ABSTRACT ABSTRACT: The paper deals with the geotechnical study and optimum ultimate pit slope design of Ashok opencast project with special reference to the highwall stability of slopes created by surface miner. It was also aimed to know the influence of slope design parameters on the safety factor by sensitivity analysis. Geotechnical mapping was done on the exposed benches of the surface mine as per the norms of International Society of Rock Mechanics. The different geo-mechanical properties of lithological units were determined. The failure analysis was done by GALENA software based on limit equilibrium method and optimum slope design was recommended. 1 INTRODUCTION The geotechnical study was conducted for the optimum ultimate pit slope design of the highwall slopes at Ashok opencast project. The mine is producing 6.5 million tonnes per year. It is located in Jharkhand state of India and being mined by Coal India Ltd. The coal is of non-coking category and is suitable for use in powerhouses. It was also aimed to know the influence of slope design parameters on the safety factor by sensitivity analysis, which tells the importance of the parameter in the critical slope. A more justified and suitable remedial measure can be planned for any critical slope after sensitivity analysis. The geotechnical characteristics of joints in overburden and coal cleats were measured on the exposed benches of the surface mine as per the norms of International Society of Rock Mechanics (ISRM 1978). The different geo-mechanical properties of lithological units were determined at the Rock and Soil Mechanics Laboratories of CMRI. Initially the average orientations of the discontinuity sets determined from the geologic structural mapping were analyzed to assess kinematically possible failure modes involving structural discontinuities in the sandstone as well as coal slope faces.
ashok coal opencast project, Dakra seam, different geo-mechanical property, discontinuity, geo-mining condition, lower dakra seam, mapping, metals & mining, optimum pit slope design, Reservoir Characterization, reservoir geomechanics, safety factor, scale failure, sensitivity analysis, slope face, slope mass, slope stability analysis, stability analysis, structural geology, Surface Mine, undrained condition, Upstream Oil & Gas, Wellbore Design, wellbore integrity
SPE Disciplines:
- Reservoir Description and Dynamics > Reservoir Characterization > Reservoir geomechanics (0.70)
- Well Drilling > Wellbore Design > Wellbore integrity (0.56)
- Reservoir Description and Dynamics > Reservoir Characterization > Exploration, development, structural geology (0.56)
- Well Drilling > Wellbore Design > Rock properties (0.55)
Abstract Spurred by the commercial success of coalbed methane activity in USA, India initiated evaluating its coal bearing basins for their coalbed methane potential in 1992. In a short span of five years it tested and flowed coalbed methane from one of the coal seams of Barakar Formation in Jharia basin. This basin is one of the member basins of the Damodar-Koel coal belt of Eastern India. The basin cover an area of 450 square kilometers and exposes sediments of the Permian, Lower Gondwana Group. It is a half graben with the southern boundary fault being more pronounced than the northern boundary fault. The tectonic setting, physio-chemical, and reservoir characteristics, depth and thickness of coal seams, and production testing of one of the coal seams has resulted in demarcating the southern part of the basin to have an attractive coalbed methane play. The central portion of this part of the basin has been prioritised for converting about 15 billion cubic meters of coalbed methane resources to reserves. Additional 15 billion cubic meters of methane resources could be converted to reserves from the adjoining areas. Introduction Production of unconventional gas from sources like coal, shales and tight reservoirs is becoming increasingly important. In U.S.A. alone, this gas accounts for 20% of the production. Coalbed methane out numbers the other sources of gas by about 65%. Spurred by the U.S. success, many coal rich countries have launched exploration and production programmes to harness this resource. India, in 1992 embarked on evaluating its coal bearing basins for their coalbed methane potential. In 1997 India tested and flowed coalbed methane for the first time from a well drilled in the Parbatpur block of Jharia basin. Since then, concerted efforts are being made to cost effectively exploit this energy source. The Government of India has announced lucrative terms and conditions to attract investments in CBM exploration and production activities (Kelafant and Stern). India, which has the 6 largest coal reserves in the world, is expected to have potential for coalbed methane. About 99% of the coal reserves of India are found in the Gondwana basins while 1% lies within the Tertiary basins (Fig.-1). Some of the Gondwana basins have been prioritised for evaluating their coalbed methane plays. The prioritisation has been done on the basis of parameters suggested by Mandal and Ghosh, wherein thirteen criterion are ranked from 1–10 with the least numeral having highest priority (Table-1). The priority that has emerged is as follows:Jharia basin East Bokaro basin Raniganj basin North Karanpura basin V. South Karanpura basin Rajmahal basin Pench-KanhanValley (Satpura Basin) Pranhita-Godavari basin The above prioritisation shows that the Rajmahal and Satpura basins are of the same rank. Priority has been given to the former because it has thicker coal seams. Since coalbed methane exploration and exploitation activity in India is still in the initial stages these activities are in the R & D phase. Concerted efforts integrating geo-scientific, reservoir and production characteristics to evaluate the coalbed methane play of Jharia basin are discussed in this paper.
Country:
- Asia > India > Jharkhand (1.00)
- Asia > India > Andhra Pradesh > Bay of Bengal (0.24)
Geologic Time:
- Phanerozoic > Cenozoic (0.48)
- Phanerozoic > Paleozoic > Permian (0.46)
Industry:
- Energy > Oil & Gas > Upstream (1.00)
- Government > Regional Government > Asia Government > India Government (0.34)
Oilfield Places:
- Oceania > Australia > Queensland > Central Highlands > Bowen Basin (0.99)
- Asia > India > Satpura Basin (0.99)
- Asia > India > Jharkhand > Rajmahal Basin (0.99)
- (4 more...)
SPE Disciplines: Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Coal seam gas (1.00)
INTRODUCTION In India, about 50 per cent of the total accidents are attributed to roof and side a Is, the proportion of fatalities on account Of roof fall and that due to side fall being almost equal. Statistics reveal that nearly 50 per cent of the total accidents have taken place by fall of roof rocks of up to 30 cm thickness and in majority of eases the area of the fallen roof rock was less than 10 sq.m.(Prasad 1975). It is generally, therefore, the immediate 30–50 cm of roof which needs close attention to ensure safety against roof falls. In this paper characteristic of weak roofs associated with the mining of some coal seams in the Raniganj Coalfield of India are given and the new technique of securing Such roofs are described. COAL MEASURE STRATA The main coalfields of India are found in the Damodar Valley and the areas adjoining and lie roughly east and west along the 24°N parallel. They belong to the Lower Gondwana period, which is subdivided in ascending order in three series: Talchir, Damodar and Panchet (Table 1). The Talch-irs lie unconformably on Archaean rocks of Precambrian age. Most of the coalfields of India have a number of coal seams. For example, Jharia coalfield has more than 25 workable coal seams, the Raniganj coalfield has seven main coal horizons in the Barakar coal measures and nine in the Raniganj coal measures and some 30 coal seams have been traced in Bokaro coalfield. These seams occur in quick succession, the parting at places being very thin; all are generally banded the bands being from a few milli-metres to several centimetres in thickness. (Table in full paper) The thicker seams have as a rule, more bands. Balls or nodules and rounded fragments of coal are not uncommon. Pyritic intrusions are also very common. The roof and floor of the seams are sandstone or shale. Fireclay as a rule is absent; if present, it is overclay. The strata consist mainly of sandstones and shales, there being various types of gradation into one another, e.g. sandy shale, shaly sandstone, etc. The percentage of sandstone in the strata is usually high (especially in the Raniganj coal measures) and may reach 88% in certain localities. Table 2 shows the relative proportions of different rock types in the Raniganj coal measures. Sandstones form massive deposits and are at times difficult to cave but they form good roof. Shale roofs on the other hand are weak and invariably present roof failure risks. SITES OF INVESTIGATIONS The present study was done in three mines, Dhemo Main, Jamuria 7 & 8 pits and Ranipur Colliery, all in Raniganj coal measures. Roof associated with Raghunathbati seam at Dhemo Main, Taltore seam roof at Jamuria 7 & 8 pits and Dishergarh seam roof at Ranipur Colliery were the subjects of study. In the Raghunathbati seam the workings 194.15m deep lay 156.66m over the goaf of Dishergarh seam.
coalfield, colliery, gallery, India, metals & mining, raghunathbati seam, raniganj coal measure, Reservoir Characterization, roof fall, roof rock, roof shale, seam, seam roof, seam roof shale, shale, shale roof, specimen, strata, strength, structural geology, taltore seam roof, Thickness, Upstream Oil & Gas
SPE Disciplines: Reservoir Description and Dynamics > Reservoir Characterization > Exploration, development, structural geology (0.47)
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