{"uid":"cap_jE02Ogid4XkaTbfW3C5hV","slug":"gassmann-inverse-dry-modulus-fluid-substitution-wave-state-calculator-ce9f0877","name":"Gassmann Inverse Dry Modulus & Fluid Substitution Wave State Calculator","description":"Calculate the complete fluid-substitution state of an explicit rock-physics model.","url":"https://detect.halowerk.com/v1/F-TD2000-GEO-INDUSTRY-B006/gassmann-inverse-dry-modulus-fluid-substitution-wave-state?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"artifact":{"type":"object","required":["gassmann"],"properties":{"gassmann":{"type":"object","required":["data","claim"],"properties":{"data":{"type":"object","required":["mineral_bulk_gpa","mineral_density","porosity","initial_saturated_bulk_gpa","shear_gpa","initial_fluid_bulk_gpa","initial_fluid_density","replacement_fluid_bulk_gpa","replacement_fluid_density"],"properties":{"porosity":{"type":"number","maximum":0.6,"minimum":0.01},"shear_gpa":{"type":"number","maximum":200,"minimum":0.001},"mineral_density":{"type":"number","maximum":10000,"minimum":100},"mineral_bulk_gpa":{"type":"number","maximum":200,"minimum":1},"initial_fluid_density":{"type":"number","maximum":5000,"minimum":1},"initial_fluid_bulk_gpa":{"type":"number","maximum":100,"minimum":0.001},"replacement_fluid_density":{"type":"number","maximum":5000,"minimum":1},"initial_saturated_bulk_gpa":{"type":"number","maximum":200,"minimum":0.01},"replacement_fluid_bulk_gpa":{"type":"number","maximum":100,"minimum":0.001}},"additionalProperties":false},"claim":{}},"additionalProperties":false}},"additionalProperties":false}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.003","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.003/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_5JNLuMhCpL5DW7GU0iS70","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.003","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Performs complete Gassmann fluid substitution on a rock-physics model, computing the full wave-state (velocities, moduli, densities) after replacing one pore fluid with another.","exampleAgentPrompt":"Run a full Gassmann fluid substitution for a sandstone with mineral bulk modulus 36 GPa, mineral density 2650 kg/m³, porosity 0.20, initial saturated bulk modulus 22 GPa, shear modulus 10 GPa, initial fluid bulk modulus 2.2 GPa (brine, density 1050 kg/m³), and replacement fluid bulk modulus 0.07 GPa (gas, density 150 kg/m³) — give me the complete wave state after the fluid swap.","exampleUseCases":[{"title":"4D Seismic Fluid Monitoring","prompt":"I need to model how P-wave velocity changes in a chalk reservoir (porosity 0.28, mineral bulk modulus 70 GPa, mineral density 2710 kg/m³, shear modulus 29 GPa, saturated bulk modulus 35 GPa) when produced brine (bulk modulus 2.5 GPa, density 1080 kg/m³) is replaced by injected CO2 (bulk modulus 0.06 GPa, density 200 kg/m³). Give me the full wave state after substitution."},{"title":"AVO Attribute Prediction for Gas Sands","prompt":"For AVO analysis I need the elastic moduli and seismic velocities for a brine-saturated sandstone (mineral bulk modulus 36 GPa, density 2650 kg/m³, porosity 0.18, saturated bulk modulus 20 GPa, shear modulus 8 GPa, initial fluid bulk modulus 2.3 GPa, density 1030 kg/m³) with the brine substituted by hydrocarbon gas (bulk modulus 0.05 GPa, density 120 kg/m³). What does the wave state look like?"},{"title":"CO2 Sequestration Seismic Modeling","prompt":"We're injecting CO2 (bulk modulus 0.08 GPa, density 250 kg/m³) into a saline aquifer sandstone (porosity 0.22, mineral bulk modulus 38 GPa, mineral density 2650 kg/m³, shear modulus 12 GPa, initial saturated bulk modulus 25 GPa, brine bulk modulus 2.4 GPa, brine density 1100 kg/m³). Can you run Gassmann substitution and return the full post-injection wave state?"}],"resultDescription":"Returns the complete post-substitution elastic and seismic wave state of the rock, including: inverse-derived dry-frame bulk modulus, new saturated bulk modulus after fluid replacement, bulk density, P-wave velocity, S-wave velocity, and derived acoustic impedance — all computed via the Gassmann equations for the specified mineral-frame and fluid properties.","failureModes":["Input values outside allowed ranges (e.g. porosity > 0.6 or < 0.01) return validation errors","Physically inconsistent inputs (e.g. saturated bulk modulus exceeding mineral bulk modulus) may cause computation failure or unphysical results","Missing required fields return schema validation errors","Negative or zero moduli values rejected by min constraints","Fluid bulk modulus exceeding mineral bulk modulus may produce unphysical dry-frame moduli"],"whenToPreferThis":"Use this endpoint when you need to perform rigorous Gassmann-equation-based fluid substitution on an explicit rock-physics model with known mineral, frame, and fluid properties. It is the right choice for reservoir characterization, 4D seismic feasibility studies, AVO modeling, and CO2 sequestration impact prediction where you have laboratory or log-derived elastic moduli and need to predict seismic response under a different fluid scenario. Prefer this over empirical velocity-porosity transforms when you have full Biot-Gassmann inputs available.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-11-04T06:40:44.256Z","isFirstParty":false,"canonicalSlug":"gassmann-inverse-dry-modulus-fluid-substitution-wave-state-calculator-ce9f0877"}