Reserves Estimation for Geopressured Gas Reservoirs

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Reserves Estimation for Geopressured Gas Reservoirs
Copyright Page
Contents
About the authors
Preface
Acknowledgments
1 Introduction
	1.1 Geopressured natural gas resources and development in China
		1.1.1 Overview of geopressured natural gas resources
		1.1.2 Gas reservoir characteristics
		1.1.3 Development status
			1.1.3.1 Sichuan Basin
			1.1.3.2 Tarim Basin
		1.1.4 Development strategies
			1.1.4.1 High-precision seismic survey
			1.1.4.2 Pilot test and production test
			1.1.4.3 Determining technical policies based on geological features
			1.1.4.4 Geology–engineering integration with geomechanics as a bridge
			1.1.4.5 Technological innovation and integrated application
	1.2 Classification of geopressured gas reservoirs
		1.2.1 Classification by depth
		1.2.2 Classification by pressure and pressure coefficient
	1.3 Reserves terms
		1.3.1 Standards in China
			1.3.1.1 Definitions
			1.3.1.2 Classification of resources/reserves
		1.3.2 Terms related to Securities and Exchange Commission reserves
	1.4 Dynamic reserves
		1.4.1 Definition
		1.4.2 Calculation methods
			1.4.2.1 Conventional methods
			1.4.2.2 Securities and Exchange Commission methods
		1.4.3 Challenges for dynamic reserve estimation
			1.4.3.1 Difficulty in performance surveillance
			1.4.3.2 Difficulty in understanding development laws
			1.4.3.3 Difficulty in determining gas reservoir parameters
2 Pressure monitoring of geopressured gas wells
	2.1 Downhole temperature and pressure monitoring of high pressure & high temperature (HPHT) gas wells
		2.1.1 Role and function of dynamic monitoring
		2.1.2 Content and means of dynamic monitoring
		2.1.3 Downhole temperature and pressure monitoring technology for HPHT gas wells
			2.1.3.1 Challenges
			2.1.3.2 Wireline-conveyed downhole temperature and pressure monitoring technology
			2.1.3.3 Safety control technology for HPHT gas well testing
			2.1.3.4 Application
	2.2 Static pressure conversion for gas wells
		2.2.1 Gas column density conversion method
		2.2.2 Static pressure gradient conversion method
		2.2.3 Wellhead static pressure conversion method
			2.2.3.1 Average temperature and average deviation factor method
			2.2.3.2 Cullender–Smith method
	2.3 Calculation of average gas reservoir pressure
		2.3.1 Arithmetic average method
		2.3.2 Weighted average method
3 Physical properties of natural gas and formation water
	3.1 Composition and properties of natural gas
		3.1.1 Composition of natural gas
		3.1.2 Equation of state of an ideal gas
			3.1.2.1 Apparent molecular weight
			3.1.2.2 Standard volume
			3.1.2.3 Density
			3.1.2.4 Gas gravity
	3.2 Behavior of real gas
		3.2.1 Natural gas deviation factor
			3.2.1.1 Correction for nonhydrocarbon components
			3.2.1.2 Correction for high-molecular-weight gases
			3.2.1.3 Direct calculation of deviation factor
			3.2.1.4 Comparison of methods
		3.2.2 Compressibility factors for natural gases
		3.2.3 Gas formation volume factor
		3.2.4 Natural gas viscosity
			3.2.4.1 The Carr–Kobayashi–Burrows method
			3.2.4.2 The Standing method
			3.2.4.3 The Dempsey method
			3.2.4.4 The Lee–Gonzalez–Eakin method
	3.3 Deviation factor of ultra-high-pressure gas
		3.3.1 DPR or DAK extrapolation method
		3.3.2 LXF-RMP (Li et al., 2010) fitting method
	3.4 Properties of formation water
		3.4.1 Formation water volume factor
		3.4.2 Formation water viscosity
		3.4.3 Natural gas solubility in water
		3.4.4 Isothermal compressibility factor of formation water
4 Material balance equation of a gas reservoir
	4.1 Material balance equation for homogeneous gas reservoirs
		4.1.1 Volumetric gas reservoir
		4.1.2 Closed gas reservoir
		4.1.3 Water-drive gas reservoir
		4.1.4 Water-drive gas reservoir with water-soluble gas
		4.1.5 Linear form of pressure depletion curve
	4.2 Material balance equation for compartmented gas reservoirs
		4.2.1 Payne method
		4.2.2 Hagoort–Hoogstra method
		4.2.3 Gao method
		4.2.4 Sun method
	4.3 Drive index of gas reservoir
	4.4 Apparent initial gas in place of gas reservoir
	4.5 Sensitivity analysis of key parameters
		4.5.1 Rock compressibility factor
			4.5.1.1 Rock compressibility factor
			4.5.1.2 Effective compressibility factor
			4.5.1.3 Cumulative rock compressibility factor
			4.5.1.4 Cumulative effective compressibility factor of gas reservoirs
		4.5.2 Size of water body
		4.5.3 Pressure depletion
		4.5.4 Apparent reservoir pressure
		4.5.5 Influence of water-soluble gas
5 Original gas in place estimations for geopressured gas reservoirs
	5.1 Classical two-segment method
		5.1.1 Hammerlindl method
			5.1.1.1 Average compressibility method
			5.1.1.2 Corrected reservoir volume method
			5.1.1.3 Relationship between the two methods
		5.1.2 Chen method
		5.1.3 Gan–Blasingame method
			5.1.3.1 Analysis method
			5.1.3.2 Analysis procedure
		5.1.4 Discussion on the time of inflection point of p/Z curve
	5.2 Linear regression method
		5.2.1 Ramagost–Farshad method
		5.2.2 Roach method
			5.2.2.1 Analysis method
			5.2.2.2 Discussion on Roach analysis method
		5.2.3 Poston–Chen–Akhtar method
			5.2.3.1 Analysis method
			5.2.3.2 Analysis procedure
		5.2.4 Becerra-Arteaga method
		5.2.5 Havlena–Odeh method
		5.2.6 Sun method
			5.2.6.1 Gas production of cumulative unit pressure drop
			5.2.6.2 Analysis procedure
	5.3 Nonlinear regression method
		5.3.1 Binary regression method
		5.3.2 Nonlinear regression method
			5.3.2.1 Ce(p)(pi−p)~Gp linear relation
			5.3.2.2 Ce(p)(pi−p)~Gp power function relation
		5.3.3 Starting point of the nonlinear regression method
	5.4 Type curve matching analysis method
		5.4.1 Ambastha method
		5.4.2 Fetkovich method
		5.4.3 Gonzalez method
		5.4.4 Sun method
		5.4.5 Multiwell production decline analysis method
	5.5 Trial-and-error analysis method
	5.6 Original gas in place estimation procedure of geopressured gas reservoirs
		5.6.1 Summary of calculation methods
		5.6.2 Recommended methods
		5.6.3 Recommended procedure
		5.6.4 Basic data preparation
		5.6.5 Comparative analysis of results
Appendices
	Appendix 1 Pertinent data of NS2B gas reservoir
	Appendix 2 Pertinent data of offshore gas reservoir
	Appendix 3 Pertinent data of Anderson L gas reservoir
	Appendix 4 Pertinent data of Gulf Coast gas reservoir
	Appendix 5 Pertinent data of GOM gas reservoir
	Appendix 6 Pertinent data of Stafford gas reservoir
	Appendix 7 Pertinent data of South Louisiana gas reservoir
	Appendix 8 Pertinent data of Example-4 gas reservoir
	Appendix 9 Pertinent data of Field-38 gas reservoir
	Appendix 10 Pertinent data of Gulf of Mexico gas reservoir
	Appendix 11 Pertinent data of ROB43-1 gas reservoir
	Appendix 12 Pertinent data of Louisiana gas reservoir
	Appendix 13 Pertinent data of SE Texas gas reservoir
	Appendix 14 Pertinent data of Cajun gas reservoir
	Appendix 15 Inflection point statistics table of 20 developed gas reservoirs by Gan–Blasingame method
	Appendix 16 Pertinent data of M1 gas reservoir
	Appendix 17 Pertinent data of M2 gas reservoir
	Appendix 18 Pertinent data of M3 gas reservoir
	Appendix 19 Pertinent data of M4 gas reservoir
	Appendix 20 Pertinent data of M5 gas reservoir
	Appendix 21 Basic principles of type curve matching analysis method
	Appendix 22 Pertinent data of Cajuna gas reservoir
	Appendix 23 Pertinent data of M6 gas reservoir
	Appendix 24 Pertinent data of M7 gas reservoir
	Appendix 25 Pertinent data of Ellenburger gas reservoir
	Appendix 26 Pertinent data of Duck Lake gas reservoir
	Appendix 27 Principles of multiple (two) meta-regression analysis
	Appendix 28 Nomenclature
	Appendix 29 Conversion relationship between SI units and other units
Bibliography
	Further reading
Index
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