- Email: [email protected]
Pressure-transient analysis for horizontal wells
82A
912152 Air permeability, measurements of the unsaturated Bandelier Tuff near Los Alamos, New Mexico Kearl, P M; Zinkl, R J; Dexter, J J; Cronk, T J Hydrol Vl17. N1/4. Sept 1990, P225-240 Unlined trenches and shafts were used for waste disposal in the Bandelier tuff, some 200m above the water table. To estimate potential for vapour phase transport, three methods were used to determine intrinsic permeability: air injection and vacuum tests in situ, and laboratory tests on cores using Klinkenberg and dynamic methods. Vacuum tests provide values in good agreement with laboratory measurements on unfractured cores. Air injection permeabilities were up to an order of magnitude greater than the others. Both the in situ methods are considered to give reliable values of intrinsic permeability.
912153 Pressure-transient analysis for horizontal wells Kuchuk, F J; Goode, P A; Brice, B W; Sherrard, D W; Thambynayagam, R K M J Pet Technol 1/42, NS. Aug 1990. P974-979. 1028-1031 Increasing use is being made of horizontal wells. The complex flow geometry of the horizontal well makes well test interpretation difficult. Interpretation techniques have been applied to data from pseudosynthetic and real tests on horizontal wells. Unique determination of system parameters is not possible from pressure data with a short testing time, typical of vertical wells, and/or production time. A drawdown test followed by a buildup test is seen to be adequate for system analysis if downhole flow rate and pressure are measured.
912154 Three-phase relative permeability of Berea sandstone Oak, M J; Baker, L E; Thomas, D C J Pet Technol V42. N8. Aug 1990, P1054-I061
912156 Two-stage treatment reduces water]oil ratio Wood, F; Dalrymple, D: McKown, K; Matthews, B Oil Gas J 1/88. N37. 10 Sept 1990, P73-75 The Arbuckle dolomite formation, Kansas, is a prolific oil producer, with good primary (matrix) permeability and secondary permeability in the form of natural fractures. This secondary permeability, coupled with strong bottom water drive mechanism, results in large quantities of water being produced along with the oil. The two stage treatment to remedy this involves first coating the pore throat surface with an amphoteric polymer to reduce permeability to water, then plugging the natural fractures with a polyacrylamide. Physical placement and chemistry are described.
912157 Response of fractured rock subject to fluid injection. Part I. Development of a numerical model Last, N C; Harper, T R Tectonophysics V172, NIl2. Jan 1990. PI-31 The selection and development of a numerical model to describe response of fractured rock having a connected fracture network to high rates of fluid flow is described. The Distinct Element Method (UDEC) was selected because of its ability to represent the fractures explicitly and to couple mechanical deformation with fluid flow. Injection from a single well into each of four basic model reservoirs has been simulated.
912158 Response of fractured rock subject to fluid injection. Part II. Characteristic behaviour Harper, T R; Last, N C Tectonophysics V172, NIl2. Jan 1990, P33-51
Three phase (water/gas/oil) flow occurs in petroleum reservoirs during enhanced recovery processes. Using a relative permeability apparatus, 2 and 3 phase relative permeabilities were measured on a water wet Berea sandstone core using a fully automated steady state method. Saturations were measured using an X ray absorption technique. Relative permeability-saturation relations are influenced by saturation history. Experimental results are compared to predictions from Stone's methods (1970, 1973).
Distinct element modelling has been used to study behaviour of naturally fractured reservoirs subject to constant rate fluid injection, under constant stress boundary conditions. Fluid leakoff through fracture walls and fracture dilation during shear were modelled. Stress and displacement histories for the coupled fluid-rock system were studied for four combinations of uniform fracture geometry and applied stress. Effects of uniform change in pore pressure on the directional nature of hydraulic conductivity in a fractured medium were characterised. Influences of injection rate, pore fluid compressibility, leakoff rate, and stiffness contrast between fractures and blocks were examined.
912155 Lagrangian simulation of coupled two-phase flows Rose. W Math Geol 1,'22. N6. Aug 1990. P641-654
912159 Response of fractured rock subject to fluid injection. Part Iii. Practical application Harper, T R; Last, N C Tectonophysics V172. NI/2, Jan 1990. P53-65
In many geotechnical problems, subsurface flow of two or more immiscible fluids in porous materials is encountered. A simplistic Lagrangian algorithm to describe steady and unsteady state multiphase transport processes, with and without viscous coupling, is presented, it uses a Jacobian transformation to convert from Eulerian to Lagrangian independent variables, thus the order of nonlinearity is reduced and finite difference computations much simplified. A numerical example is illustrated which highlights the importance of including coupling effects.where present.
High rate injection will cause a pressure fluctuation with time, attributable to shear and/or dilatancy. Generalised modelling using the UDEC code has indicated factors controlling the directional nature of flow in naturally fractured reservoirs, and these are tabulated and discussed. The need to use fully coupled models to adequately represent the dynamic changes is emphasised. The sensitivity of the naturally fractured system to even short periods of high rate injection and the resulting apparently irreversible changes in fracture conductivity and stress state are demonstrated.
~' 1991 Pergamon Press pie. Reproduction not permitted
912152 Air permeability, measurements of the unsaturated Bandelier Tuff near Los Alamos, New Mexico Kearl, P M; Zinkl, R J; Dexter, J J; Cronk, T J Hydrol Vl17. N1/4. Sept 1990, P225-240 Unlined trenches and shafts were used for waste disposal in the Bandelier tuff, some 200m above the water table. To estimate potential for vapour phase transport, three methods were used to determine intrinsic permeability: air injection and vacuum tests in situ, and laboratory tests on cores using Klinkenberg and dynamic methods. Vacuum tests provide values in good agreement with laboratory measurements on unfractured cores. Air injection permeabilities were up to an order of magnitude greater than the others. Both the in situ methods are considered to give reliable values of intrinsic permeability.
912153 Pressure-transient analysis for horizontal wells Kuchuk, F J; Goode, P A; Brice, B W; Sherrard, D W; Thambynayagam, R K M J Pet Technol 1/42, NS. Aug 1990. P974-979. 1028-1031 Increasing use is being made of horizontal wells. The complex flow geometry of the horizontal well makes well test interpretation difficult. Interpretation techniques have been applied to data from pseudosynthetic and real tests on horizontal wells. Unique determination of system parameters is not possible from pressure data with a short testing time, typical of vertical wells, and/or production time. A drawdown test followed by a buildup test is seen to be adequate for system analysis if downhole flow rate and pressure are measured.
912154 Three-phase relative permeability of Berea sandstone Oak, M J; Baker, L E; Thomas, D C J Pet Technol V42. N8. Aug 1990, P1054-I061
912156 Two-stage treatment reduces water]oil ratio Wood, F; Dalrymple, D: McKown, K; Matthews, B Oil Gas J 1/88. N37. 10 Sept 1990, P73-75 The Arbuckle dolomite formation, Kansas, is a prolific oil producer, with good primary (matrix) permeability and secondary permeability in the form of natural fractures. This secondary permeability, coupled with strong bottom water drive mechanism, results in large quantities of water being produced along with the oil. The two stage treatment to remedy this involves first coating the pore throat surface with an amphoteric polymer to reduce permeability to water, then plugging the natural fractures with a polyacrylamide. Physical placement and chemistry are described.
912157 Response of fractured rock subject to fluid injection. Part I. Development of a numerical model Last, N C; Harper, T R Tectonophysics V172, NIl2. Jan 1990. PI-31 The selection and development of a numerical model to describe response of fractured rock having a connected fracture network to high rates of fluid flow is described. The Distinct Element Method (UDEC) was selected because of its ability to represent the fractures explicitly and to couple mechanical deformation with fluid flow. Injection from a single well into each of four basic model reservoirs has been simulated.
912158 Response of fractured rock subject to fluid injection. Part II. Characteristic behaviour Harper, T R; Last, N C Tectonophysics V172, NIl2. Jan 1990, P33-51
Three phase (water/gas/oil) flow occurs in petroleum reservoirs during enhanced recovery processes. Using a relative permeability apparatus, 2 and 3 phase relative permeabilities were measured on a water wet Berea sandstone core using a fully automated steady state method. Saturations were measured using an X ray absorption technique. Relative permeability-saturation relations are influenced by saturation history. Experimental results are compared to predictions from Stone's methods (1970, 1973).
Distinct element modelling has been used to study behaviour of naturally fractured reservoirs subject to constant rate fluid injection, under constant stress boundary conditions. Fluid leakoff through fracture walls and fracture dilation during shear were modelled. Stress and displacement histories for the coupled fluid-rock system were studied for four combinations of uniform fracture geometry and applied stress. Effects of uniform change in pore pressure on the directional nature of hydraulic conductivity in a fractured medium were characterised. Influences of injection rate, pore fluid compressibility, leakoff rate, and stiffness contrast between fractures and blocks were examined.
912155 Lagrangian simulation of coupled two-phase flows Rose. W Math Geol 1,'22. N6. Aug 1990. P641-654
912159 Response of fractured rock subject to fluid injection. Part Iii. Practical application Harper, T R; Last, N C Tectonophysics V172. NI/2, Jan 1990. P53-65
In many geotechnical problems, subsurface flow of two or more immiscible fluids in porous materials is encountered. A simplistic Lagrangian algorithm to describe steady and unsteady state multiphase transport processes, with and without viscous coupling, is presented, it uses a Jacobian transformation to convert from Eulerian to Lagrangian independent variables, thus the order of nonlinearity is reduced and finite difference computations much simplified. A numerical example is illustrated which highlights the importance of including coupling effects.where present.
High rate injection will cause a pressure fluctuation with time, attributable to shear and/or dilatancy. Generalised modelling using the UDEC code has indicated factors controlling the directional nature of flow in naturally fractured reservoirs, and these are tabulated and discussed. The need to use fully coupled models to adequately represent the dynamic changes is emphasised. The sensitivity of the naturally fractured system to even short periods of high rate injection and the resulting apparently irreversible changes in fracture conductivity and stress state are demonstrated.
~' 1991 Pergamon Press pie. Reproduction not permitted