--> Waking Up The Sleeping Giants: Investigation Of Geomechanic Uncertainty For Ccs In The Era Of Big Data

AAPG Asia Pacific Region GTW, Pore Pressure & Geomechanics: From Exploration to Abandonment

Datapages, Inc.Print this page

Waking Up The Sleeping Giants: Investigation Of Geomechanic Uncertainty For Ccs In The Era Of Big Data

Abstract

Trillions cubic feet of gas resources with high content of carbon dioxide (>30%) lies untouched within the border of Indonesia. Extraction of the sweet gas requires disposal of the impurities without venting it to the atmosphere. Amongst the proposed solutions, Carbon Capture and Storage (CCS) which injects carbon dioxide into subsurface reservoir plays an important role in handling the greenhouse gas. Storage site selection requires robust subsurface evaluation which includes comprehensive reservoir geomechanic investigation. Pressure perturbation caused by the injection could endanger the operation by causing unintended migration. However, in light of the infancy of the CCS industry, the required data for geomechanic investigation may be insufficient or even not available at all. Thus, the geomechanic properties has to be rigorously approached in an unconventional way by using a combination of sensitivity analysis, big data and advanced uncertainty analysis. The goal of this study is to present a workflow that could be used to assess feasibility of CCS sites all around the world.

Reservoir simulation coupled with geomechanic parameter result from East Natuna storage site candidate was selected. Geomechanic properties of reservoir with analogous geological setting was collected from numerous references to setup the experiment by providing different cases to the reservoir simulation. Variance based sensitivity analysis was conducted in order to find out which parameters has the most prominent effect to the cumulative CO2 injection. Statistical proxy model was created with volumetric strain, displacement vector and cumulative gas injection. The two geomechanic parameters was selected because it was able to represents fundamental rock mechanical properties such as Young’s Modulus, Poisson’s Ratio and Biot’s coefficient through an objective function. The result shows approximately ±2 TCF of CO2 could be injected into the reservoir. Depending on the injection scheme, the fluid injection may cause 0.1 – 0.8 ft of vertical displacement. However, the operation could still be carried out with acceptable risk without causing any 'unintended migration' from the subsurface dedicated storage.