Impact of Natural Hazards on Oil and Gas Extraction

by Bagirov, E.; Lerche, Ian

• ISBN13: 9780306462856
• ISBN10: 0306462850
• Format: Hardcover
• Copyright: 1999-12-01
• Publisher: Kluwer Academic Pub

Summary

There exists a broad range of natural hazards, including seismicity, faulting, fracturing, mud volcano eruptions, mud island motion, overpressure and lateral stress. These natural hazards, along with others, affect the exploration and production of hydrocarbons, especially in offshore operations. For each potential hazard, an estimation of their frequencies of occurrence, in addition to a quantitative assessment of the possible consequences, must be made. Impact of Natural Hazards on Oil and Gas Extraction: The South Caspian Basin provides technical details regarding these natural hazards, using the South Caspian Basin as a model. Here, the variation of natural hazards is documented in a geological setting. Accordingly, the scales of possible damage for each situation can be compared, and an understanding provided of the influence each hazard type has on every other.

Table of Contents

Location Maps	xiii
Introduction	1	(14)
Introduction To The Quantitative Assessment of Geological Hazards	1	(1)
Some Information on the South Caspian Basin	2	(13)
Historical Oil Review	2	(2)
Tectonical Review	4	(4)
Sedimentation rates of the South Caspian Basin	8	(3)
Mud Volcanoes and Diapirs	11	(4)
Earthquake Hazards	15	(16)
Seismicity Hazards	16	(12)
Frequency and Strength Distributions of Major Earthquakes	16	(6)
Directional Distribution of Longitudinal Earthquakes	22	(3)
Occurrences of Seismic Dislocations, Causes, and Spatial Orientations	25	(2)
An Assessment Procedure for Seismic Hazards to Installation Foundations	27	(1)
Conclusions	28	(3)
Fault and Fracture Hazards	31	(18)
Deformation of Sedimentary Beds Around a Mud Diapir	32	(5)
Interrelated Seismic and Mud Volcano Hazards	37	(3)
Fracture Formations Associated with Mud Volcano Eruptions	40	(4)
Conclusions	44	(2)
Appendix A:	46	(3)
Modeling Strain	46	(1)
Modeling Stress	47	(1)
Modeling fracturing of sediments	48	(1)
Mud Volcano Eruptions and Flame Hazards	49	(74)
Statistical Hazard Assessment from the Historical Record	49	(26)
Descriptive Information	50	(1)
Onshore versus Offshore Statistics	51	(11)
Probability of a New Volcano Developing in the Chirag Area	62	(1)
Distance distribution of individual groups of gryphons from a common eruptive center	63	(2)
Waiting Time predictions and mud volcano frequency of eruptions in the Chirag Field	65	(1)
Determination of eruptive intensity	66	(1)
Variability of observed eruptions with time	67	(5)
Evaluation of the average number of eruptions per year	72	(1)
Expected number of yearly eruptions at the Chirag area	73	(2)
Flaming Eruptions. Historical Review	75	(6)
Factors Associated with Flaming Eruptions	81	(9)
Composition of mud volcano gases	81	(3)
Flame Ignition During Eruptions	84	(3)
Flame Height Distribution	87	(1)
Emitted Gas Volume Distribution	88	(2)
Gas Volumes Emitted from Volcanic Mud	90	(1)
Flame Hazard Distances	90	(15)
A Simple Model of Flame Column Distortion	91	(3)
Heating Hazards	94	(2)
Test Cases	96	(1)
The Eruption of Duvanny Island in 1961	96	(1)
Case History A: High Angle Flames	97	(2)
Flames at 70° to the Horizontal	99	(1)
Flames at 80° to the Horizontal	100	(3)
Case History B: Low Angle Flames	103	(2)
Conclusions	105	(5)
Appendix A. Solutions to Equations (4.15a) and (4.15b) under the initial conditions of Equations (4.16)	110	(4)
Downward Flowing Wind (sinψ>0)	110	(2)
Horizontal Flowing Wind (sinψ=0)	112	(1)
Upward Flowing Wind (sinψ<0)	113	(1)
The Length of the Flame Column	114	(1)
Appendix B. Heating Effects	114	(3)
Radiation	115	(1)
Convection	116	(1)
Appendix C. Summaries of Some Historical Flame Observations	117	(6)
Mud Flow Hazards	123	(26)
Distribution of Variables related to Mud Volcano Flows	125	(4)
Dependence of Variables related to Mud Volcano Eruptions	129	(4)
Predicting the possible scales of mud flows based on dynamical models	133	(7)
Conclusions	140	(2)
Appendix A. Mathematical Formulation	142	(7)
Gravity Current Flow	142	(2)
Mud Transport	144	(1)
Mud Deposition	145	(1)
Erosion	146	(3)
Hydrate Hazards	149	(22)
General Hydrate Dissociation Conditions	149	(2)
Hydrate Properties. Pressure-Temperature Stability Fields	151	(2)
Phase Diagrams and Evolution Tracks	153	(9)
Evolutionary tracks under sediment deposition-redeposition conditions	153	(3)
Evolutionary tracks under glacial-interglacial conditions	156	(2)
Evolutionary tracks under sea-level rise and/or fall	158	(1)
Ethane enrichment in hydrates	159	(1)
Aeolian effects: winter/summer and hydrate evaporation/reformation	160	(2)
Hazard Factors for Hydrates	162	(2)
Seismic Effects and Mud Flows	164	(3)
Conclusions	167	(1)
Appendix: A Quantitative Procedure for Hydrate Composition Determination from Seismic Data	168	(3)
Gas Hazards	171	(46)
Geology and Input Parameters	173	(4)
Model Results	177	(32)
Water Flow	188	(7)
Gas Flow	195	(14)
Hazard Aspects	209	(1)
Conclusions	210	(1)
Appendix A: Mathematical Considerations	211	(6)
Single Parameter Distributions	212	(3)
Numerical Procedures	215	(2)
Breccia Hazards	217	(34)
General Observations	217	(1)
Numerical Illustrations	218	(21)
Class 1. Onshore Ejecta	219	(1)
Planar Emission and Impact	219	(3)
Raised Crater and Planar Impact	222	(5)
Walled Crater Ejection and Planar Impact	227	(4)
Depressed Crater Emission onto a Higher Impact Plane	231	(2)
Class 2. Ejecta under Offshore Conditions	233	(1)
Island Emission into the Ocean	233	(5)
Submarine Emission	238	(1)
Conclusions	239	(1)
Appendix A	239	(12)
Single Rock Fragment Motion in Air	239	(2)
Breccia Ejection in Air from a Walled Crater	241	(2)
Breccia Ejecta from a Depressed Crater	243	(1)
Submarine Breccia Ejecta	244	(4)
Initial Distribution Considerations	248	(1)
Initial Mass Distributions	248	(1)
Initial Ejection Speeds	248	(3)
Overpressure and Lateral Stress in Sedimentary Formations	251	(32)
Overpressure Hazards	251	(15)
Results of Modeling along W-E 12-second cross-section	252	(1)
Present-day Fluid Pressures	252	(2)
Present-day Excess Pressure	254	(1)
Results of N-S cross-section Modeling	255	(1)
Present-day Fluid Pressures	255	(1)
Present-day Excess Pressure	256	(1)
Results of 1-D Modeling	257	(6)
Fixed depths, variable excess pressure with time	263	(1)
Isobaric pressures, variable depths with time	264	(2)
Horizontal Stress	266	(8)
Conclusions	274	(1)
Appendix A	275	(8)
The Governing Equations for Elastic Flexure with Constant or Variable Plate Rigidity	275	(3)
The Inverse Tomographic Procedure	278	(5)
Mud Island and Mud Diapir Motion Hazards	283	(10)
Historical Observation of Mud Island Occurrence	283	(4)
Mud Diapirs and Semi-Permanent Islands	287	(4)
Evanescent Mud Islands	287	(1)
Mud Islands formed due to mud diapir rise	288	(1)
Submarine/Aeolian Islands	289	(1)
Dry Push-Out Islands	289	(1)
Almost permanent islands	290	(1)
Lateral Diapir Motion	290	(1)
Hazard Aspects of Island Motion	291	(2)
Hazards of Variability in Reservoir Characteristics for South Caspian Oil Fields	293	(34)
Introduction	293	(1)
Specific Distributions of Reservoir Characteristics	294	(26)
Geometrical Distributions	294	(1)
Combined Onshore and Offshore Fields	294	(1)
Producing Thickness	294	(2)
Areal Distribution	296	(1)
Volumetric Distribution	296	(1)
Reservoir Depth Distribution	297	(1)
Onshore or Offshore Geometric Distributions	297	(1)
Physical Parameter Distributions	298	(1)
Porosity	299	(1)
Permeability	299	(1)
Oil Viscosity	299	(1)
Reserves, Recovery Factors, and Water Content	299	(11)
Reserves Versus Horizons and Depths	310	(1)
Reserves Versus Reservoir Thicknesses and Areas	311	(1)
Reserves and Production Versus Depth	311	(9)
Spatial Distribution of Economic Oil Field Horizons	320	(2)
Discussion and Conclusion	322	(2)
Appendix A. List of Onshore and Offshore Oil Fields used together with producing horizons/field	324	(3)
Natural Hazards in Hydrocarbon Exploration and Production Assessments	327	(8)
Catastrophic Loss in Exploration Assessments	328	(2)
Catastrophic Loss after Oil is Found	330	(3)
Conclusions	333	(2)
Summary of Potential Natural Hazards in the South Caspian Basin	335	(4)
References	339	(8)
Subject Index	347