# US 2014/0156239 A1 · Engineered methodology for design verification and validation of ultra-deep high pressure high temperature oil and gas well control equipment > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0156239 A1 - Document ID: US20140156239A1 - Status: Published application - Kind: A1 - Application number: 14/174,946 - Filed: 2014-02-07 - Published: 2014-06-05 - Earliest claimed: 2011-09-01 - Assignees: McMoRan Oil & Gas, LLC - Applicants: McMoRan Oil & Gas, LLC - Inventors: Richard Anthony Sukup; J. Robert Sims; Ravi M. Krishnamurthy; David B. Lewis - Web page: https://patentgrep.com/patent/US20140156239A1 ## CPC - A63B 71/12: for the body or the legs {, e.g. for the shoulders (A63B71/081 takes precedence)} - E21B 41/00: Equipment or details not covered by groups E21B15/00 - E21B40/00 - G06F 30/17: Mechanical parametric or variational design - G06F 30/23: using finite element methods [FEM] or finite difference methods [FDM] - E21B 33/03: Well heads; Setting-up thereof - E21B 33/06: Blow-out preventers {, i.e. apparatus closing around a drill pipe, e.g. annular blow-out preventers (rotating blow-out preventers E21B33/085)} - G01N 3/02: Details - A63B: APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT (apparatus for passive exercising, massage A61H) - 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) - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract A process for the verification and validation testing of equipment and components for drilling, completion, production and general well construction (typically such as subsurface safety valves, wellhead trees, blowout preventers and wireline pressure control equipment) to determine the suitability of such equipment for use in oil and gas wells in high pressure high temperature environments. In particular, the process of the present invention comprises, among other steps, the steps of analyzing such components using an elastic-plastic finite element model with respect to certain preset load conditions and establishing stable model convergence, conducting a ratcheting assessment by running analysis on such model on all components that exhibit local plasticity, and examining all components to determine fatigue sensitive locations and subjecting such components to a fatigue analysis. The process may further comprise a process for qualifying the materials to be used in the manufacture of the equipment components with respect to their ability to withstand high pressure and high temperature environmental conditions. ## Claims ### Claim 1 A method for design verification and validation of surface and sub-surface oil and gas equipment components comprising the steps of: (a) analyzing the components for global static strength and local plasticity with an elastic-plastic finite element model, the analysis using preset load conditions and the least favorable combination of dimensional tolerances for each component based on an initial mesh density and comprising the steps of: (i) confirming that the design of the component results in a stable model convergence using all preset load conditions; (ii) conducting a mesh refinement study on stressed portions of the components, where further refinement in mesh density will result in less than a pre-selected mesh refinement percentage change in plastic strain; (iii) confirming that stressed portions of the components identified by the model have strain limit damage that is less than a set strain limit damage amount; (b) conducting a ratcheting assessment by running an elastic-perfectly plastic analysis with the model on all equipment components that exhibit local plasticity at a maximum combination of preset load conditions to determine resistance to ratcheting by applying the maximum preset load conditions to such components to demonstrate at least one ratcheting criterion; and (c) examining all components to determine fatigue sensitive locations and subjecting components exhibiting fatigue sensitive locations to a fatigue analysis. ### Claim 2 (depends on 1) The method of claim 1 wherein the high pressure high temperature surface and sub-surface oil and gas equipment components tested are selected from the group of subsurface safety valves, wellhead trees, blowout preventers, or wireline pressure control equipment. ### Claim 3 (depends on 1) The method of claim 1 wherein the ratcheting criteria are selected from the group comprising a condition of no plastic action in the component, a condition where an elastic core exists at a primary load bearing boundary of the component, or a condition in which there is no permanent change in the dimensions of the component. ### Claim 4 (depends on 1) The method of claim 1 wherein the pre-selected mesh refinement percentage change is less than 5%. ### Claim 5 (depends on 1) The method of claim 1 wherein the pre-selected mesh refinement percentage change is less than 2%. ### Claim 6 (depends on 1) The method of claim 1 wherein the mesh refinement process refines an initial mesh density by a factor of 2. ### Claim 7 (depends on 1) The method of claim 1 wherein the set strain limit damage amount is 1. ### Claim 8 (depends on 1) The method of claim 1 wherein the ratcheting assessment includes the application of the preset load conditions to the component through at least 5 cycles. ### Claim 9 (depends on 1) The method of claim 1 wherein the elastic-plastic element finite element model is applied to the equipment components including all cladding overlay covering such equipment components. ### Claim 10 (depends on 1) The method of claim 1 wherein the preset load conditions include a set of load combinations based on the high temperature high pressure environment. ### Claim 11 (depends on 1) The method of claim 1 wherein the fatigue analysis further comprises a step of performing a fracture analysis on the equipment component to determine whether the equipment component satisfies certain fracture criteria wherein such fracture criteria are based on minimum flaw size criteria and established toughness data. ### Claim 12 (depends on 1) The method of claim 1 wherein the fatigue analysis further comprises the step of determining whether the equipment component satisfies fatigue criteria wherein such fatigue criteria are based on minimum flaw size criteria, established or inert environment toughness data and concurrent stress corrosion crack growth data. ### Claim 13 (depends on 12) The method of claim 12 wherein the fatigue analysis further determines whether a pre-existing flaw in the equipment component identified in the analysis grows through any cladding overlay covering such equipment component to ensure that the flaw does not penetrate the cladding overlay. ### Claim 14 (depends on 1) The method of claim 1 further comprising a materials qualification process to determine whether the materials used for the design of the equipment components are suitable for the high pressure high temperature environment. ### Claim 15 (depends on 14) The method of claim 14 wherein the materials qualification process experimentally establishes true stress-strain curve inputs for such materials. ### Claim 16 An apparatus designed for use in oil and gas wells in a high pressure high temperature environment, including for drilling, completion and production operations, the apparatus including components analyzed using a computer system including a processor, memory, input/output devices, and software, the software including instructions for execution of the computer system, having the characteristics comprising: (a) when analyzed using the computer system for global static strength and local plasticity using an elastic-plastic finite element model with respect to certain preset load conditions and using the least favorable combination of dimensional tolerances for each component and based on an initial mesh density, the components: (i) achieve a stable model convergence using all preset load conditions; (ii) exhibit a mesh density where further refinement in mesh density of stressed portions of the components will result in less than a pre-selected mesh refinement percentage change in plastic strain; (iii) achieve a strain limit damage for the stressed portions of the components identified by the model that is less than a set strain limit damage amount; (b) when subjected to a ratcheting assessment by elastic-perfectly plastic analysis using the computer system, components that exhibit local plasticity at the maximum combination of preset load conditions are resistant to ratcheting using the preset load conditions by demonstrating at least one ratcheting criterion; and (c) achieve acceptance criteria when the fatigue sensitive locations of the components are subjected to a fatigue analysis using the computer system. ### Claim 17 (depends on 16) The apparatus of claim 16 further comprising components that are analyzed that are not exposed to well produced fluids in an actual well environment. ### Claim 18 (depends on 16) The apparatus of claim 16 further comprising components that are analyzed that are not exposed to well kill fluids in an actual well environment. ### Claim 19 (depends on 16) The apparatus of claim 16 further comprising components that are analyzed that are not exposed to drilling and completion fluids in an actual well environment. ### Claim 20 (depends on 16) The apparatus of claim 16 wherein the components are selected from the group of subsurface safety valves, wellhead trees, blowout preventers, or wireline pressure control equipment. ### Claim 21 (depends on 16) The apparatus of claim 16 wherein the components are further subjected to a materials qualification process to determine whether the materials used for the design of the equipment components are suitable for the high pressure high temperature environment. ### Claim 22 (depends on 21) The apparatus of claim 21 wherein the materials qualification process experimentally establishes true stress-strain curve inputs for such materials. ### Claim 23 (depends on 16) The apparatus of claim 16 wherein the ratcheting criteria are selected from the group comprising a condition of no plastic action in the component, a condition where an elastic core exists at a primary load bearing boundary of the component, or a condition in which there is no permanent change in the dimensions of the component. ### Claim 24 (depends on 16) The apparatus of claim 16 wherein the pre-selected mesh refinement percentage change is less than 5%. ### Claim 25 (depends on 16) The apparatus of claim 16 wherein the pre-selected mesh refinement percentage change is less than 2%. ### Claim 26 (depends on 16) The apparatus of claim 16 wherein the mesh refinement process refines an initial mesh density by a factor of 2. ### Claim 27 (depends on 16) The apparatus of claim 16 wherein the set strain limit damage amount is 1. ### Claim 28 A computer system for the design verification and validation of surface and sub-surface oil and gas equipment components including a processor, memory, input/output devices, and software, the software including instructions for execution of the computer system, the instructions comprising: (a) analyzing the components for global static strength and local plasticity with an elastic-plastic finite element model, the analysis using preset load conditions and the least favorable combination of dimensional tolerances for each component based on an initial mesh density and comprising the steps of: (i) confirming that the design of the component results in a stable model convergence using all preset load conditions; (ii) conducting a mesh refinement study on stressed portions of the components, where further refinement in mesh density will result in less than a pre-selected mesh refinement percentage change in plastic strain; (iii) confirming that stressed portions of the components identified by the model have strain limit damage that is less than a set strain limit damage amount; (b) conducting a ratcheting assessment by running an elastic-perfectly plastic analysis with the model on all equipment components that exhibit local plasticity at a maximum combination of preset load conditions to determine resistance to ratcheting by applying the maximum preset load conditions to such components to demonstrate at least one ratcheting criterion; and (c) examining all components to determine fatigue sensitive locations and subjecting components exhibiting fatigue sensitive locations to a fatigue analysis. ### Claim 29 (depends on 28) The computer system of claim 28 wherein the high pressure high temperature surface and sub-surface oil and gas equipment components tested are selected from the group of subsurface safety valves, wellhead trees, blowout preventers, or wireline pressure control equipment. ### Claim 30 (depends on 28) The computer system of claim 28 wherein the ratcheting criteria are selected from the group comprising a condition of no plastic action in the component, a condition where an elastic core exists at a primary load bearing boundary of the component, or a condition in which there is no permanent change in the dimensions of the component. ### Claim 31 (depends on 28) The computer system of claim 28 wherein the pre-selected mesh refinement percentage change is less than 5%. ### Claim 32 (depends on 28) The computer system of claim 28 wherein the pre-selected mesh refinement percentage change is less than 2%. ### Claim 33 (depends on 28) The computer system of claim 28 wherein the mesh refinement process refines an initial mesh density by a factor of 2. ### Claim 34 (depends on 28) The computer system of claim 28 wherein the set strain limit damage amount is 1. ### Claim 35 (depends on 28) The computer system of claim 28 wherein the instructions further comprise performing a materials qualification process to determine whether the materials used for the design of the equipment components are suitable for the high pressure high temperature environment. ### Claim 36 (depends on 35) The computer system of claim 35 wherein the materials qualification process experimentally establishes true stress-strain curve inputs for such materials. ### Claim 37 (depends on 1) The method of claim 1 further comprising, as a first and second step, the steps of: (aa) providing at least one component; (bb) obtaining data from the component to generate a computer readable representation of the component. ### Claim 38 (depends on 37) The method of claim 37, wherein the data obtained from the component is derived from a physical testing technique. ### Claim 39 (depends on 1) The method of claim 1 further comprising, as a first and second step, the steps of: (aa) providing materials of a type used for construction of the components; (bb) obtaining data from the materials using physical testing techniques to generate computer readable data inputs for use in the modeling of the components. ### Claim 40 (depends on 16) The apparatus of claim 16 wherein the apparatus is constructed prior to the performance of the analysis by the computer system and data obtained from the apparatus using physical testing techniques is used to generate a computer readable representation of the apparatus for use in the analysis by the computer system. ### Claim 41 (depends on 16) The apparatus of claim 16 wherein materials of a type to be used to construct the components are tested using physical testing techniques and data obtained from the testing is used to generate computer readable data inputs for use in the analysis by the computer system. ### Claim 42 (depends on 28) The computer system of claim 28 further comprising, as a first instruction, the instruction comprising generating a computer readable representation of the components obtained from data developed from the performance of physical testing techniques on the components. ### Claim 43 (depends on 28) The computer system of claim 28 further comprising, as a first instruction, the instruction comprising generating computer readable data inputs obtained from data developed from the performance of physical testing techniques on the materials of a type to be used to construct the components.