Innovative Exploration Methods for Minerals, Oil, Gas, and Groundwater for Sustainable Development

By Jayanta Bhattacharya

Innovative Exploration Methods for Mineral, Oil, Gas, and Groundwater for Sustainable Development provides an integrated approach to exploration encompassing geology, geophysics, mining, and mineral processing. In addition, groundwater exploration is included, as it is central to the development of earth resources. As the demand for coal, minerals, oil and gas, and water continues to grow globally, researchers must prioritize sustainable exploration methods. Old technologies are being replaced speedily and exploration work has become fast, focused, meaningful, and readily reproducible keeping in pace with the changing global scenario. The themes of exploration of energy resources, exploration of minerals, groundwater exploration and processing and mineral engineering are separated out into sections and chapters included in these sections include case studies focusing on tools and techniques for exploration. Innovative Exploration Methods for Mineral, Oil, Gas, and Groundwater for Sustainable Development gives insight to modern concepts of exploration for those working in the various fields of energy, mineral, and groundwater exploration.

• Presents innovative research that will both challenge and complement the traditional concepts of exploration
• Covers a wide range of instruments and their applications, as well as the tools and processes that need to be followed for modern exploration work
• Includes research on groundwater exploration with a focus on conservation and sustainable exploration and development

• Language: English
• Publisher: Elsevier Science
• Release date: Dec 3, 2021
• ISBN: 9780128239995

Book preview

Chapter 1

Energy resource (Coal, Shale Gas, Geothermal, Oil, Gas)

Chapter Outline

1.1 Gasification of high ash Indian coals in fluidized bed gasifier 5

1.1.1 Introduction 5

1.1.2 Experimental 5

1.1.2.1 Experimentation in fluidized bed gasification pilot plant 6

1.1.3 Results and discussion 6

1.1.3.1 Variation of gasification performance parameters with gasification temperature 7

1.1.3.2 Variation of gasification performance parameters with air/coal ratio 10

1.1.3.3 Variation of gasification performance parameters with effect of coal feed rate 12

1.1.3.4 Variation of gasification performance parameters for different coals 12

1.1.4 Conclusions 15

References 15

1.2 Exploration of mining method for coal extraction in developed bord and pillar property by powered support long wall equipment 17

1.2.1 Introduction 17

1.2.2 Shortwall mining 17

1.2.3 Advantages of the method over conventional B&P mining 18

1.2.4 Selection of site for shortwall 18

1.2.5 Geo-mining parameters in an Indian mine 18

1.2.6 Physiomechanical properties of overlying roof rocks 19

1.2.7 Premining scientific studies and observations 19

1.2.7.1 Field observation 19

1.2.7.2 Numerical modeling 19

1.2.7.3 Support system 20

1.2.7.4 Gate roads 21

1.2.8 Production, productivity, and profitability 21

1.2.8.1 Some salient information 21

1.2.9 Future scope on production and productivity 23

1.2.10 Induced caving 23

1.2.11 Strata control 26

1.2.11.1 At the surface 27

1.2.12 Strata control, monitoring, and observations 27

1.2.13 Conclusions 27

1.3 Exploration of shale gas in India – Prospects and challenges 29

1.3.1 Introduction 29

1.3.2 Shale gas exploration 31

1.3.3 Shale gas resource potential in India 33

1.3.4 Proterozoic basins – potential areas for closer look 35

1.3.5 Tackling shale gas challenges in India 36

1.3.6 Conclusion 37

References 38

1.4 Synergy through integrated geophysical acquisition for geothermal and hydrocarbon exploration and production 43

1.4.1 Introduction 43

1.4.2 System parameters 43

1.4.2.1 Advanced MT 45

1.4.2.2 Broadband MT 45

1.4.2.3 Mini MT and AMT 45

1.4.2.4 MT and TEM 46

1.4.2.5 Reservoir monitoring 46

1.4.3 Processing and interpretation 47

1.4.4 Applications 47

1.4.4.1 Establishing monitoring system characteristics 48

1.4.4.2 Example of geothermal exploration 49

1.4.5 Conclusions 52

Acknowledgments 53

References 53

1.5 3D seismic expression of a paleo channel within Barail Argillaceous and its hydrocarbon prospect: Makum field 55

1.5.1 Introduction 55

1.5.2 Methodology 56

1.5.3 Seismic signature 56

1.5.4 Discussion 60

Reference 60

1.6 A case study of reservoir parameter estimation in Norne oil field, Norway by using Ensemble Kalman Filter (EnKF) 61

1.6.1 Introduction 61

1.6.2 Objectives 62

1.6.3 Tasks 62

1.6.4 Parameter estimation 62

1.6.5 Quantifying uncertainty in production forecasts 63

1.6.6 EnKF methodology 63

1.6.7 Managing the uncertainties 64

1.6.8 Advantages of EnKF 64

1.6.9 Sequential Gaussian simulation 64

1.6.10 Case study 65

1.6.11 Norne oil field 65

1.6.12 General geology of Norne field 65

1.6.13 Structure of the Norne field 67

1.6.14 Production history of the Norne field 67

1.6.15 Semisynthetic case: Norne 67

1.6.16 Discussion of the cases on the basis of EnKF 68

1.6.17 Discussion and result 71

Acknowledgments 75

References 76

1.7 Coal bed methane: Changing India's gas market 79

1.7.1 Introduction 79

1.7.2 CBM as an energy source 79

1.7.3 CBM extraction technology 81

1.7.4 Challenges in CBM extraction 83

1.7.4.1 Technical challenges 83

1.7.5 Environmental impact 83

1.7.6 Land acquisition difficulties 84

1.7.7 Hydrofracturing 84

1.7.8 Pricing and marketing of CBM in India 85

1.7.9 Future prospects of CBM 85

References 86

1.8 Identification of gas bearing sweet-spots within complex reservoir by integrating modern geophysical measurements - case studies from upper Assam fields 87

1.8.1 Introduction 87

1.8.2 Wireline logging technologies, methodologies, and case studies 88

1.8.2.1 Reservoir saturation logging 88

1.8.2.2 Shear sonic imager logging 89

1.8.2.3 Nuclear magnetic resonance logging 93

1.8.3 Discussions 99

References 99

1.9 Evolution and future prospects for coalbed methane and coal mine methane in India: Approaches for addressing mine safety, climate change and energy security 101

1.9.1 Introduction 101

1.9.2 Genesis, storage, and transport of methane in coal 102

1.9.2.1 Genesis 102

1.9.2.2 Storage 103

1.9.2.3 Transport 103

1.9.3 Coal and lignite deposits in India 104

1.9.4 Coal mining in India 106

1.9.5 Mine safety issues and gassiness of coal seams in India 107

1.9.5.1 Mine safety issues 107

1.9.5.2 Gassiness of coal seams in India 107

1.9.6 Climate change interlinkages 110

1.9.7 Coalbed methane and coal mine methane as mitigating measures 112

1.9.8 Coalbed methane development in India 113

1.9.8.1 Status of coal mine methane in India 115

1.9.8.2 Some case studies 116

1.9.8.3 Ghusick colliery (Sripur area) 118

1.9.8.4 Mines in Mohuda Sub-Basin, Jharia coalfield 120

1.9.8.5 Amlabad colliery, East Jharia basin 122

1.9.9 Conclusion 123

Acknowledgments 124

References 124

1.1

Gasification of high ash Indian coals in fluidized bed gasifier

P.D. Chavan, G. Sahu, A. Banerjee, V. Chauhan, N.K. Gupta, S. Saha, S. Datta, P. Datta, P.K. Singh

Gasification and Liquefaction Research Group, CSIR-Central Institute of Mining and Fuel Research Institute, Dhanbad, Jharkhand, India

Abstract

Fluidized bed gasification (FBG) technology appeared to be better suited compared to other types of gasifier to handle high ash coals. Due to low temperature operation, in-depth investigations on the gasification of high ash coals in FBG are essential. In the present study, coal samples from four different coal fields of India have been selected. Further, experiments have been conducted in FBG pilot plant to understand gasification performance in actual plant. In the present study, variations of performance parameters with operating conditions and coals have been discussed.

Keywords

Fluidized bed gasification (FBG) technology; High ash coal; Noncoking coal

1.1.1 Introduction

Globally clean coal technologies are of major focus as majority of coal produced is having high ash content and causing environmental pollution (Takematsu, 1991). This problem is more pronounced as Indian coals are not only high in ash but also the association of mineral matter with carbon matrix is very close and in dispersed form (Patil-Shinde et al., 2014; Chavan et al., 2012). At the same time, coal-based energy generation meets around 70 percent of our energy needs (Chavan et al., 2012). Now, to move forward toward cleaner energy production mechanism and to attain energy security of the country utilizing the potentiality of Indian coals, gasification technology seems to be a promising option. Gasification process is capable to recycle and utilize the carbon dioxide from various sources as gasifying agent and thereby reducing greenhouse gas in the atmosphere. Thus, this route can bring out several environmental advantages over conventional coal utilization technologies (Saha, 2013). Moreover, Indian clean energy development policy is emerging with continual development programs which include intensive investigations on the gasification of high ash Indian coals.

Fluidized bed gasification (FBG) technology appears to be better suited compared to other types of gasifier to handle high ash coals. It is known that the fluidized bed gasifier provides better contact between solid and gaseous reactants, which is favorable for maximum carbon conversion (Chavan et al., 2012). However, fluidized bed gasifier operates in dry ash removal mode. Due to this, it needs to be operated at a lower temperature, which may result in unconverted carbon in the fly ash and bottom ash. To encounter such envisaged situation arising out of low temperature operation, in-depth investigations on the gasification reactivity/kinetics vis-a-vis factors related to gasification performance are very much needed. In this direction, present investigation has been proposed to study the effects of operating parameters in actual plant.

1.1.2 Experimental

In the present study, noncoking coal samples from four different coal fields of India have been selected. Around four tons of ROM coal was collected from each coal field and transported to experimentation site by truck. The coal samples have been reduced in size manually and then crushed in jaw crusher and reduced to 25 mm. Then, it has been crushed in double roller crusher and screened to get -2 mm size. Further, representative sample from each coal has been taken and crushed to desired size for coal characterization. For FBG experimentation, the requisite amount of coal about 100 kg having -2 mm size has been prepared as discussed above for each experiment.

Selected coal samples were characterized for its basic properties such as proximate analysis. Proximate analysis are carried out following Indian standards viz. IS: 1350 (Part-I) 1984, IS: 1350 (Part-III) 1969, IS: 1350 (Part-IV/Sec-1) 1974, IS: 1350 (Part-IV/Sec-2) 1975. These properties of selected coals are shown in Table 1.1.1.

Table 1.1.1

*Proximate analysis on air dried basis.

1.1.2.1 Experimentation in fluidized bed gasification pilot plant

Experiments have been designed to study the role of gasification activation energy of selected coals on gasification performance of coals. For this purpose, experiments have been conducted in a FBG pilot plant under different operating conditions, i.e., gasifier temperature, coal feed rate, air/coal ratio, steam feed rate, etc. The FBG pilot plant (Fig. 1.1.1) used for present study has capacity between 10 and 20 kg/h coal feed rate at a gauge pressure of 3 kg/cm² and at a temperature of up to 1000°C. Gasification process parameters for different experiments are shown in Table 1.1.2. The gasifier plant consists of the following major subsystems:

• Reactor

• Coal feeding system

• Gaseous reactant supply system

• Bottom ash extraction system

• Cyclone with ash collection system

• Gas cooling and cleaning system

• Exhaust system and flare stack

Figure 1.1.1 Fluidized bed gasification test facility.

Table 1.1.2

1.1.3 Results and discussion

From the gasification data generated in the FBG pilot plant, gasification performance parameters such as product gas generation, kg/kg of coal; heating value of product gas, kcal/Nm³ and carbon conversion, percent have been estimated. Further, variations of these performance parameters with operating conditions have been studied and findings are discussed in the following paragraphs.

In the gasification experiments in FBG, operating parameters like coal feed rate, kg/h; air/coal ratio, kg/kg of coal; steam/coal ratio, kg/kg of coal; ash withdrawal rate, kg/h; gasifier bed temperature, °C are important input parameters that affects above mentioned gasification performance parameters. In the present study, steam/coal ratio is varied within very narrow range due to constrain of the test facility, so it is not considered as an affecting input parameter. Effects of other process parameters are discussed in detail in the following paragraphs.

1.1.3.1 Variation of gasification performance parameters with gasification temperature

An attempt has been made to study the variation of gasification performance parameters like CO and H2 generation, the product gas generation per kg of coal, product gas heating value and carbon conversion with gasification temperature. The results obtained are shown in Fig. 1.1.2A to D.

Figure 1.1.2 Variation of (A) CO+H 2 generation, (B) product gas generation, (C) Product gas heating value and (D) carbon conversion with gasification temperature.

Fig. 1.1.2A and B shows variation of the CO and H2 and product gas generation per kg of coal with gasification temperature. From Fig. 1.1.2A, it is observed that as gasification temperature increases, CO and H2 generation per kg of coal increases for all the studied coals. Fig. 1.1.2B shows the same trend where product gas generation per kg of coal increases with gasifier bed temperature. As observed in TGA study, reactivity of coal increases with increase in gasification temperature. This may result in faster endothermic gasification reactions to generate more CO and H2 per kg of coal. Also higher gasification temperature may result in faster pyrolysis as well as combustion of more coal to generate increased CO2 which gets converted to CO through Boudouard reaction. This may be the reason behind the increase in CO and H2 at higher gasification temperature. Further, increase in reactivity at higher temperature may result in increased carbon conversion as indicated by the Fig. 1.1.2D. At higher temperature, more CO2 get converted to two molecules of CO through endothermic Boudourd reaction and char-steam reaction to produce more CO and H2, resulting in more product gas per kg of coal and. This may also result in more carbon conversion at higher gasification temperature. These observations find support from various literatures. Lee et al. (2002) have reported that rate of several endothermic reactions increases with rise in gasification temperature. This results in increased carbon conversion and subsequently more product gas per kg of feed coal. This observation is also supported by Pinto et al. (2003) and Ponzio et al. (2006).

Fig. 1.1.2C shows the variation in product gas heating value with gasification temperature. As temperature increases, product gas heating value first increase up to 900 to 950°C temperatures and further slightly declines. As temperature increases, more CO and H2 get generated and this generated CO and H2 contributes to increase heating value of the product gas. However, to attain higher temperature, more air enters into the system for additional combustion. This results in more carbon utilization from combustion reaction and creates deficiency of the carbon for gasification reactions, which reduces the heating value of the product gas. Also, more N2 enters into the system along with extra air required to attain higher temperature, which acts as a major diluent. Due to these reasons, overall heating value of product gas decreases as temperature increases after certain value. This observation also finds support from the findings reported by Pinto et al. (2003), Lee et al. (2002), and Kim et al. (1997).

1.1.3.2 Variation of gasification performance parameters with air/coal ratio

Variation in gasification performance parameter with air/coal ratio has been studied and results obtained are shown in Fig. 1.1.3A to D. Fig. 1.1.3A and B shows variation in CO+H2 generation and product gas generation per kg of coal with air/coal ratio. From Fig. 1.1.3A, it is observed that, initially CO and H2 generation increases with the increase in air/coal ratio and further, it shows decreasing trend. Fig. 1.1.3B indicates that as air/coal ratio increases product gas generation per kg of coal increases.

Figure 1.1.3 Variation of (A) CO+H 2 generation, (B) product gas generation, (C) product gas heating value and (D) carbon conversion with air feed rate.

Fig. 1.1.3C shows the variation in product gas heating value with air/coal ratio. From this figure it is observed that initially product gas heating value increases with the increase in air/coal ratio. However, further it decreases with the increase in air/coal ratio after certain limit. Fig. 1.1.3D shows plots for variation in carbon conversion with air/coal ratio. From these plots it is observed that carbon conversion increases with air/coal ratio.

The reasons behind above mentioned findings may be due to the enhancement in coal combustion reactions with increased air, thereby resulting in increased temperature. As discussed in an earlier section, increase in temperature may be responsible for increased carbon conversion as well as more product gas generation. Apart from these reasons, the increase in product gas per kg of coal may be due to extra nitrogen from the increased air feed.

Initially, increased air/coal ratio may increase product gas heating value due to rise in CO and H2 generation. However, further decrement is observed with increase in the air/coal ratio. This may be due to production of more CO2 as well as the dilution effect of extra nitrogen from air. Apart from this, reduction in heating value of the product gas may happen due to re-combustion of fuel species in product gas by excess oxygen. However, carbon conversion increases with air/coal ratio. Similar observations are reported by several researchers worldwide (Pinto et al., 2003, Lee et al., 2002, Ocampo et al., 2003).

Ocampo et al. (2003) have reported that the carbon conversion increases almost linearly with the air/coal ratio. Kim et al. (1997), Pinto et al. (2003), Lee at al. (2002), Quan et al. (1991), and Foong et al. (1981) have also reported similar results during gasification studies in the fluidized bed gasifier. They have also reported that CO and H2 concentration, product gas generation as well as carbon conversion increases with the increase in air/coal ratio however, CO and H2 generation per kg of coal and the product gas heating value decreases with excess air/coal ratio.

1.1.3.3 Variation of gasification performance parameters with effect of coal feed rate

Variation of gasification performance parameters with coal feed rate has been studied. The results obtained are shown in Fig. 1.1.4A to D. Fig. 1.1.4A to D shows variation of CO+H2, product gas generation per kg of coal, product gas heating value, and carbon conversion with coal feed rate respectively.

Figure 1.1.4 Variation of (A) CO+H 2 generation, (B) product gas generation, (C) product gas heating value and (D) carbon conversion with coal feed rate.

From these plots, it is observed that CO and H2 generation, the product gas generation per kg of coal as well as carbon conversion decreases with increase in coal feed rate. However, the coal feed rate has not shown much effect on product gas heating value. The negative effect on the product gas generation and carbon conversion may be due to the reduced residence time of coal particles in gasifier bed with increased coal feed rate. This may happen due to the fact that in a fluidized bed, the entire bed material gets mixed quickly and thoroughly as it enters in the bed. Due to these reasons, residence time of coal particles in bed may get reduced resulting in lower carbon conversion. Further, this results in lower product gas generation per kg of feed coal. This indicates that for low temperature gasification sufficient residence time is essential to get maximum carbon conversion and product gas generation per kg of coal.

Kim et al. (1997) have also observed similar results during their gasification studies. They have reported that product gas generation as well as carbon conversion decreases with increase in coal feed rate.

These findings show that variation in the coal feed rate controls the residence time in the gasifier and thus the residence time has large effects on gasification rate as well as carbon conversion.

1.1.3.4 Variation of gasification performance parameters for different coals

An attempt has been made to study the variation of gasification performance with coal have been studied and results obtained are plotted in Fig. 1.1.5A to D. Fig. 1.1.5A and B shows variation in CO+H2 and product gas generation for different coals. Fig. 1.1.5C and D shows variation in product gas heating value and carbon conversion with coal.

Figure 1.1.5 Variation of (A) CO+H 2 generation, (B) product gas generation, (C) product gas heating value and (D) carbon conversion with coal.

From Fig. 1.1.5A and B, it is observed that CO+H2 generation and product gas generation per kg of coal decreases from Coal-1 to Coal-4 in a sequential manner. As discussed earlier, mineral matter acts as diluent in feed coal lowering carbon and volatile matter per kg of coal. It becomes responsible for lowering the carbonaceous material in the coal matrix. Also, mineral matter in coal absorbs more heat generated in an autothermal gasifier to raise and maintain its temperature. In addition to this, high mineral matter in feed coal imposes heat loss through bottom ash and fly ash also to the surrounding. Therefore, more coal feed rate is required or more coal gets utilized for the combustion reaction to fulfill these heat requirements. This may result in a lower CO+H2 generation and lower product gas generation per kg of coal as observed in Fig. 1.1.5A and B.

Further, due to increased coal feed rate for high ash coals, requirement of coaly matter can be fulfilled and heating value of product gas remains unaffected as shown in Fig. 1.1.5C. However, due to increased coal feed rate, residence time of coal particles gets reduced. This may result in lower carbon conversion as observed in Fig. 1.1.5D. Apart from this, as discussed in earlier sections, ash content also blocks the pores in the coal matrix causing a decrease in the exposed specific surface area and thus reduced reactivity. This may result in lower carbon conversion. Similar observations are reported by different researchers (Davidson et al. (1983), Kyotani et al. (1993), Haykiri-Acma et al. (1999), Mims, (1990). Yun et al. (2007) have reported that mineral matter in coal acts as diluents and affect product gas generation in a negative manner.

1.1.4 Conclusions

Fluidized bed gasification study was conducted in a pilot scale fluidized bed gasifier with four different coals under different operating conditions i.e. gasifier temperature, coal feed rate, air/coal ratio, steam feed rate, etc. The FBG pilot plant used for present study has capacity between 10 and 20 kg/h coal feed rate at a gauge pressure of 3 kg/cm² and at a temperature of up to 1000°C. Following conclusions are made based on the observations:

• Gas yield (kg/kg of coal), CO + H2 generation (kg/kg of coal) and carbon conversion increase with the increase in gasification temperature. However, heating value of the product gas was found to increase up to 950°C and further decreased slightly with the increasing gasification temperature.

• CO + H2 generation and product gas heating value first increased with the increasing air/coal ratio up to a certain limit beyond that these parameters were found to decrease. However, gas generation and carbon conversion increased with the increasing air/coal ratio

• It was observed that CO and H2 generation, the product gas generation per kg of coal as well as carbon conversion decreases with increase in coal feed rate. However, the coal feed rate has not shown much effect on product gas heating value.

• CO + H2 generation, product gas yield and carbon conversion were found to decrease with the increasing ash content of the feed coal. Further, heating value of the product gas remains unaffected with the increasing ash content of the feed coal.

The impact of the present work is concurrently significant not only in finding effect of different operating parameters on gasification performance of different Indian coals, but also, it is very much relevant in the utilization of Indian coals for value addition of the coals through advanced clean coal route.

References

Chavan, P.D., 2012. Development of data-driven models for fluidized-bed coal gasification process. Fuel. 93, 44–51.

Chavan, P., Datta, S., Saha, S., Sahu, G., Sharma, T., 2012. Influence of high ash Indian coals in fluidized bed gasification under different operating conditions. Solid. Fuel. Chem. 46, 108–113.

Davidson, R., 1983. Mineral effects in coal conversion. ICTIS/TR22. IEA Coal Research, London.

Foong, S.K., Cheng, G., Watkinson, A.P., 1981. Spouted bed gasification of Western Canadian coals. Can. J. Chem. Eng. 59, 625–630.

Haykiri-Acma, H., Yavuz, R., Ersoy-Mericboyu, A., Kucukbayrak, S., 1999. Effect of mineral matter on the reactivity of lignite. Thermochim. Acta 342, 79–84.

Kyotani, T., Kutoba, K., Cao, J., Yamashita, H., Tomita, A., 1993. Combustion and CO2 gasification of coals in a wide temperature range. Fuel Process. Technol. 36, 209–217.

Kim, Y.J., Lee, J.M., Kim, S.D., 1997. Coal gasification characteristics in an internally circulating fluidized bed with draught tube. Fuel 76 (11), 1067–1073.

Lee, W.-J., Kim, S.-D., Song, B.-H., 2002. Steam gasification of an Australian bituminous coal in a fluidized bed. Korean J. Chem. Eng. 19 (6), 1091–1096.

Mims, C., 1990. Catalytic gasification of carbon: fundamental and mechanism, in Fundamental issues in control of carbon gasification reactivity. J. Lahaye and Ehrburger. Kluwer Academic Publishers, London, pp. 383–407.

Ocampo, A., Arenas, E., Espinel, J., Londono, C., Aguirre, J., Perez, J.D., 2003. An experimental study on gasification of Colombian coal in fluidised bed. Fuel 82, 161–164.

Patil-Shinde, V., et al., 2014. Artificial intelligence based modeling of high ash coal gasification in a pilot plant scale fluidized bed gasifier. I & EC Res. 53 (49),