# US 2017/0285221 A1 · Generating dynamically calibrated geo-models in green fields > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0285221 A1 - Document ID: US20170285221A1 - Status: Published application - Kind: A1 - Application number: 15/404,674 - Filed: 2017-01-12 - Published: 2017-10-05 - Earliest claimed: 2016-01-22 - Assignees: Saudi Arabian Oil Company - Applicants: Saudi Arabian Oil Company - Inventors: Babatope Kayode; Faisal Thawad - Web page: https://patentgrep.com/patent/US20170285221A1 ## CPC - G01V 20/00: Geomodelling in general - E21B 43/00: Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells (applicable only to water E03B) - E21B 47/06: Measuring temperature or pressure - E21B 49/00: Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells - G06F 17/11: for solving equations {, e.g. nonlinear equations, general mathematical optimization problems (optimization specially adapted for a specific administrative, business or logistic context G06Q10/04)} - G01V: GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS (means for indicating the location of accidentally buried, e.g. snow-buried, persons A63B29/02) - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract Techniques to generate dynamically calibrated geo-models green fields are described. A geo-model representing a field on which wells are drilled in a hydrocarbon-bearing formation adjusted to generate multiple adjusted geo-models. Each adjusted geo-model represents a variant of the numerical geo-model. Using each adjusted geo-model, multiple simulated rates of change of bottomhole pressures over time in a well drilled in the hydrocarbon-bearing formation are determined. A measured rate of change of bottomhole pressures over time in the well is compared with the multiple simulated rates of change of bottomhole pressures over time in the well. Based on a result of the comparing, the adjusted geo-model that yielded simulated rates of change of bottomhole pressures that best matched the measured rate of change of bottomhole pressure is identified. A geological property associated with the best-match adjusted geo-model is determined and presented in a geological property contour map of the hydrocarbon-bearing formation. ## Claims ### Claim 1 A computer-implemented method comprising: (a) receiving a numerical geo-model representing a field on which wells are drilled in a hydrocarbon-bearing formation, the numerical geo-model comprising a plurality of grid blocks representing a portion of the formation, the plurality of grid blocks associated with a value representing a geological property of the portion of the formation; (b) generating a plurality of adjusted numerical geo-models from the initial received numerical geo-model, wherein each adjusted numerical geo-model represents a variant of the received numerical geo-model; (c) determining a plurality of simulated rates of change of bottomhole pressures over time in a well drilled in the hydrocarbon-bearing formation, each simulated rate of change of bottomhole pressures over time determined using a volumetric flow rate over time through the well, each simulated rate of change of bottomhole pressures over time in the well associated with an adjusted numerical geo-model; (d) receiving a measured rate of change of bottomhole pressures over time in the well; (e) comparing the measured rate of change of bottomhole pressures over time to the plurality of simulated rates of change of bottomhole pressures over time in the well; (f) based on a result of the comparing, identifying a first simulated rate of change of bottomhole pressures over time from the plurality of simulated rates of change of bottomhole pressures over time; (g) identifying an adjusted geological property value of the portion of the formation, wherein adjusting the first simulated rate of change of bottomhole pressures over time based on the adjusted geological property value decreases the difference between the first simulated rate of change of bottomhole pressures over time and the measured rate of change of bottomhole pressures; and (h) providing the adjusted geological property value to be presented in a geological property contour map of the hydrocarbon-bearing formation. ### Claim 2 (depends on 1) The method of claim 1, wherein generating an adjusted numerical geo-model of the plurality of adjusted numerical geo-models comprises: simulating volumetric flow through the plurality of grid blocks of a first size; measuring simulated bottomhole pressures over time responsive to the volumetric flow through the plurality of grid blocks until stabilization of rate of change of bottomhole pressures over time; and applying a time-shift shift to the rate of change of bottomhole pressures over time to correspond to a rate of change of bottomhole pressures over time simulated for the volumetric flow through a second plurality of grid blocks of a second size smaller than the first size. ### Claim 3 (depends on 1) The method of claim 1, wherein the measured rate of change of bottomhole pressures over time is obtained by measuring changes in bottomhole pressure over time in the well drilled in the hydrocarbon-bearing formation. ### Claim 4 (depends on 1) The method of claim 1, wherein a difference between the first simulated rate of change of bottomhole pressures over time and the measured rate of change of bottomhole pressures over time is less than each difference between each remaining simulated rate of change of bottomhole pressures over time and the measured rate of change of bottomhole pressures over time. ### Claim 5 (depends on 1) The method of claim 1, wherein, for each of the plurality of simulated rates of change of bottomhole pressures over time, a simulated rate of change of bottomhole pressure over time (Dervi) is determined as: Derv i = Δ   P i + 1 - Δ   P i - 1 Sn  ( Δ   t i + 1 ) - Sn  ( Δ   t i - 1 ) , wherein ΔP represents a change of bottomhole pressure and Δt represents a change of time. ### Claim 6 (depends on 4) The method of claim 4, wherein Sn is determined as: Sn  ( Δ   t ) = ∑ i = 1 n - 1  q i - q i - 1 q n - q n - 1   log   ( t n - t i + Δ   t ) + log   Δ   t wherein q represents volumetric flow rate, and t represents time. ### Claim 7 (depends on 1) The method of claim 1, wherein identifying the first simulated rate of change of bottomhole pressures over time comprises determining, for each simulated rate of change of bottomhole pressures over time, a sum of squares error relative to the measured rate of change of bottomhole pressures over time. ### Claim 8 (depends on 7) The method of claim 7, wherein the sum of squares error (MQI) relative to the measured rate of change of bottomhole pressures is determined using MQI=√{square root over (Σ(Xobs−Xsim)2/N)}, wherein Xobs is the measured ra rate of change of bottomhole pressures over time, Xsim is the simulated rate of change of bottomhole pressures over time, and N is the total number of pressure derivative values. ### Claim 9 (depends on 7) The method of claim 7, further comprising: determining a plurality of sum of squares errors for the plurality of simulated rates of changes of bottomhole pressures over time, each sum of squares error relative to the measured rate of change of bottomhole pressures over time; and ranking the plurality of sum of squares errors in an ascending order of the plurality of sum of squares errors. ### Claim 10 (depends on 9) The method of claim 9, further comprising assigning a simulated rate of change of bottomhole pressures having the lowest sum of square errors of the plurality of sum of square errors as the first simulated rate of change of bottomhole pressures. ### Claim 11 (depends on 1) The method of claim 1, wherein the well is a first well included in a plurality of wells drilled at respective locations in the hydrocarbon-bearing formation, wherein the adjusted geological property value is a first adjusted geological property value, and wherein the method further comprises: for each remaining well of the plurality of wells, repeating steps (a), (b), (c), (d), (e), (f), (g) and (h); and receiving a plurality of adjusted geological property values including the first adjusted geological property value and an adjusted geological property value for each remaining well. ### Claim 12 (depends on 11) The method of claim 11, further comprising: generating a contour map of the hydrocarbon-bearing formation using the plurality of adjusted geological property values and the locations in the hydrocarbon-bearing formation at which the plurality of wells are drilled; and displaying, on the contour map, a first plurality of identifiers representing the respective plurality of adjusted geological property values at a second plurality of identifiers representing the respective locations. ### Claim 13 (depends on 1) The method of claim 1, further comprising: (i) performing a fine adjustment to the adjusted geological property value of the portion of the formation; (j) modifying the first simulated rate of change of bottomhole pressures based on the fine adjustment to the adjusted geological property value; and iterating steps (i) and (j) to decrease a difference between the first simulated rate of change of bottomhole pressures and the measured rate of change of bottomhole pressures. ### Claim 14 A system comprising: one or more processors; and a computer-readable medium storing instructions executable by the one or more processors to perform operations comprising: (a) receiving a numerical geo-model representing a field on which wells are drilled in a hydrocarbon-bearing formation, the numerical geo-model comprising a plurality of grid blocks representing a portion of the formation, the plurality of grid blocks associated with a value representing a geological property of the portion of the formation; (b) generating a plurality of adjusted numerical geo-models from the initial received numerical geo-model, wherein each adjusted numerical geo-model represents a variant of the received numerical geo-model; (c) determining a plurality of simulated rates of change of bottomhole pressures over time in a well drilled in the hydrocarbon-bearing formation, each simulated rate of change of bottomhole pressures over time determined using a volumetric flow rate over time through the well, each simulated rate of change of bottomhole pressures over time in the well associated with an adjusted numerical geo-model; (d) receiving a measured rate of change of bottomhole pressures over time in the well; (e) comparing the measured rate of change of bottomhole pressures over time to the plurality of simulated rates of change of bottomhole pressures over time in the well; (f) based on a result of the comparing, identifying a first simulated rate of change of bottomhole pressures over time from the plurality of simulated rates of change of bottomhole pressures over time; (g) identifying an adjusted geological property value of the portion of the formation, wherein adjusting the first simulated rate of change of bottomhole pressures over time based on the adjusted geological property value decreases the difference between the first simulated rate of change of bottomhole pressures over time and the measured rate of change of bottomhole pressures; and (h) providing the adjusted geological property value to be presented in a geological property contour map of the hydrocarbon-bearing formation. ### Claim 15 (depends on 14) The system of claim 14, wherein the measured rate of change of bottomhole pressures over time is obtained by measuring changes in bottomhole pressure over time in the well drilled in the hydrocarbon-bearing formation. ### Claim 16 (depends on 14) The system of claim 14, wherein a difference between the first simulated rate of change of bottomhole pressures over time and the measured rate of change of bottomhole pressures over time is less than each difference between each remaining simulated rate of change of bottomhole pressures over time and the measured rate of change of bottomhole pressures over time. ### Claim 17 (depends on 14) The system of claim 14, wherein, for each of the plurality of simulated rates of change of bottomhole pressures over time, a simulated rate of change of bottomhole pressure over time (Dervi) is determined as: Derv i = Δ   P i + 1 - Δ   P i - 1 Sn  ( Δ   t i + 1 ) - Sn  ( Δ   t i - 1 ) , wherein ΔP represents a change of bottomhole pressure and Δt represents a change of time. ### Claim 18 (depends on 17) The system of claim 17, wherein Sn is determined as: Sn  ( Δ   t ) = ∑ i = 1 n - 1  q i - q i - 1 q n - q n - 1   log   ( t n - t i + Δ   t ) + log   Δ   t wherein q represents volumetric flow rate, t represents time. ### Claim 19 (depends on 14) The system of claim 14, wherein identifying the first simulated rate of change of bottomhole pressures over time comprises determining, for each simulated rate of change of bottomhole pressures over time, a sum of squares error relative to the measured rate of change of bottomhole pressures over time. ### Claim 20 (depends on 19) The system of claim 19, wherein the sum of squares error (MQI) relative to the measured rate of change of bottomhole pressures is determined using MQI=√{square root over (Σ(Xobs−Xsim)2/N)}, wherein Xobs is the measured a rate of change of bottomhole pressures over time, Xsim is the simulated rate of change of bottomhole pressures over time, and N is the total number of pressure derivative values. ### Claim 21 A computer-readable medium storing instructions executable by one or more processors to perform operations comprising: (a) receiving a numerical geo-model representing a field on which wells are drilled in a hydrocarbon-bearing formation, the numerical geo-model comprising a plurality of grid blocks representing a portion of the formation, the plurality of grid blocks associated with a value representing a geological property of the portion of the formation; (b) generating a plurality of adjusted numerical geo-models from the initial received numerical geo-model, wherein each adjusted numerical geo-model represents a variant of the received numerical geo-model; (c) determining a plurality of simulated rates of change of bottomhole pressures over time in a well drilled in the hydrocarbon-bearing formation, each simulated rate of change of bottomhole pressures over time determined using a volumetric flow rate over time through the well, each simulated rate of change of bottomhole pressures over time in the well associated with an adjusted numerical geo-model; (d) receiving a measured rate of change of bottomhole pressures over time in the well; (e) comparing the measured rate of change of bottomhole pressures over time to the plurality of simulated rates of change of bottomhole pressures over time in the well; (f) based on a result of the comparing, identifying a first simulated rate of change of bottomhole pressures over time from the plurality of simulated rates of change of bottomhole pressures over time; (g) identifying an adjusted geological property value of the portion of the formation, wherein adjusting the first simulated rate of change of bottomhole pressures over time based on the adjusted geological property value decreases the difference between the first simulated rate of change of bottomhole pressures over time and the measured rate of change of bottomhole pressures; and (h) providing the adjusted geological property value to be presented in a geological property contour map of the hydrocarbon-bearing formation. ### Claim 22 (depends on 21) The medium of claim 21, wherein the well is a first well included in a plurality of wells drilled at respective locations in the hydrocarbon-bearing formation, wherein the adjusted geological property value is a first adjusted geological property value, and wherein the operations further comprising: for each remaining well of the plurality of wells, repeating steps (a), (b), (c), (d), (e), (f) and (g); and receiving a plurality of adjusted geological property values including the first adjusted geological property value and an adjusted geological property value for each remaining well. ### Claim 23 (depends on 22) The medium of claim 22, the operations further comprising: generating a contour map of the hydrocarbon-bearing formation using the plurality of adjusted geological property values and the locations in the hydrocarbon-bearing formation at which the plurality of wells are drilled; and displaying, on the contour map, a first plurality of identifiers representing the respective plurality of adjusted geological property values at a second plurality of identifiers representing the respective locations.