Caprock Integrity Study of the 2nd Wall Creek Reservoir: A case Study from Teapot Dome, Wyoming

Quintal Nunes, Jhony César ; Cobos Mora, Jacquelin Elizabeth

4. term

Oil and Gas Technology, Master

2017

2017-06-08

149

Sikker langtidslagring af CO2 i undergrunden afhænger af caprocken, det forseglende bjergartslag over et reservoir, som forhindrer væsker og gas i at trænge op. Hvis forseglingen svigter, kan CO2 slippe ud og udgøre en risiko for mennesker og miljø. Denne undersøgelse bruger en tværfaglig tilgang, der kombinerer geologi, petrofysik (egenskaber ved bjergarter), rockfysik og geomekanik (hvordan bjergarter deformeres), for at vurdere caprockens trækstyrke ved 2nd Wall Creek-reservoiret i Teapot Dome, Wyoming. Feltet er valgt på grund af god datatilgængelighed og flere gennemførte pilotprojekter for CO2-lagring. Første del af arbejdet er udført i Schlumbergers Techlog og bygger på wireline-loggingdata fra 18 boringer. Her beregnes caprockens petrofysiske og mekaniske egenskaber. Disse oplysninger integreres for at estimere en sprødhedsindeks, som er knyttet til caprockens trækstyrke (modstand mod at revne). En neuronal analyse i IPSOM bruges til at klassificere caprocken efter duktilitet (tendens til at deformere) og sprødhed (tendens til at revne). Til sidst indlæses egenskaberne i Petrel, en integreret undergrundsplatform, for at opbygge et 3D-kort over caprockens sprødhed og duktilitet. Kortet peger på mulige borelokationer til CO2-lagring. De samlede resultater viser, at 2nd Wall Creek-reservoiret kan betragtes som en lovende kandidat til et CO2-sekvestreringsprojekt.

Safe, long-term CO2 storage in the subsurface depends on the caprock, the sealing rock layer above a reservoir that keeps fluids and gas from moving upward. If the seal fails, CO2 could escape and pose safety and environmental risks. This study uses a multidisciplinary approach that combines geology, petrophysics (rock properties), rock physics, and geomechanics (how rocks deform) to assess the tensile strength of the caprock at the 2nd Wall Creek reservoir in the Teapot Dome field, Wyoming. The site was chosen because of strong data availability and several CO2 sequestration pilot projects carried out there. In the first phase, Schlumberger’s Techlog platform and wireline logging data from 18 wells were used to compute the caprock’s petrophysical and mechanical properties. These were integrated to estimate a brittleness index, a measure linked to tensile strength (resistance to cracking). A neural analysis in IPSOM was then used to classify the caprock as more ductile (tends to deform) or more brittle (tends to crack). Finally, the properties were loaded into the Petrel subsurface platform to build a 3D map of caprock brittleness and ductility, indicating potential drilling locations for CO2 storage. Overall, the results suggest that the 2nd Wall Creek reservoir is a promising candidate for a CO2 sequestration project.

[This abstract was generated with the help of AI]

Caprock ; CO2 storage ; Petrophysics ; geology ; rock physics ; geomechanics ; Teapot Dome ; 2nd Wall Creek Reservoir ; ductility ; brittleness ; brittleness index ; rock strength ; IPSOM ; Techlog ; Petrel

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