EAGE/SBGF First EAGE Conference on The Roadmap to Low Carbon Emission in Brazil
- Conference date: November 25-26, 2024
- Location: Rio de Janeiro, Brazil
- Published: 25 November 2024
-
-
Assessment of Mineral Composition Uncertainty on the CO2 Mineralization in Mafic Rocks
More LessAuthors V. Mello and M.V. MachadoSummaryMafic rocks might present a high potential for permanent carbon storage through CO2 mineralization. The main reason for that is the abundance of reactive minerals in their composition. However, the mineral composition can significantly vary spatially within an igneous interval and from one geologic site to another. Here, we quantify the impact of rock composition, regarding the mafic minerals, on the long-term field-scale CO2 entrapment. The results point out relevant differences in the efficiency of mineral trapping, even in the short term, considering a timeframe of 30 years.
-
-
-
-
Leakage Risk Assessment in Rollover Structures of the Sable Subbasin, Offshore Nova Scotia: Implications for CCS
More LessAuthors K.T. Martyns-Yellowe, F.W. Richards, D.E. O’Connor, T.B. Kelly, G.D. Wach, L. Damascena and C. RibeiroSummaryOn the Scotian Margin, most of the successful commercial gas discoveries occur in simple closures within rollover structures of the Sable Subbasin where they have been produced from the high net-to-gross Missisauga Formation reservoirs. In the absence of the simple closure in this stratigraphic interval, a favorable juxtaposition of strata with the presence of extensive thick shales play a role in guaranteeing the success of key reservoirs that have been intercepted by faults.
This paper uses a 3D geocellular model of two Structure drilled offshore Nova Scotia, populated with key reservoir parameters to demonstrate potential risks associated with fault leakage in the rollover. Using a previously constructed static model taken to dynamic modelling in these structures, a hypothesis that the residual saturations on logs will match the residual saturations in the dynamic models and will correspond to large water tests with very little gas is tested.
Results from the dynamic modeling demonstrate an upward and outward cross-fault, stair stepping migration of gas through the reservoirs in the high net-to-gross shallow to intermediate sections of one of the structures after a minimum of 25 to 50 years of steady injection and equilibration. Post simulation, the presence of some residual gas saturation after the injection and equilibration phase supports initial observations of upto 50% gas saturation from log analysis of key reservoirs. In the other modelled structure, there is very little movement of residual fluids across the fault when geomechanical modelling is explored.
In conclusion, results of the dynamic modelling confirm that residual trapping holds some significance in the sequestration of CO2 in faulted rollover anticlines where fault leakage may be a risk. Modelling applications done on the Rollover Structures in this study may be applicable to prospective margins where CO2 sequestration in rollover anticlines is being considered such as the Brazilian Margin and its conjugates in the Southern Atlantic.
-
-
-
Cabiúnas-São Tomé CCS Pilot Project in Campos Basin, Brazil: A 4D Petroelastic Modeling Feasibility Study
More LessAuthors L. Alvim and L. PereiraSummaryDue to continuous global rising of industrialization and energy demand, greenhouse gas emissions are an increasingly environmental concern. The Kyoto Protocol and more recently Paris Agreement, signed in 1997 and 2015, respectively, are examples of major international treaties aimed at tackling global warming, leading to a world governments pressure to reduce carbon dioxide emissions at atmosphere. In that sense, Carbon Capture, Utilization and Storage (CCUS), a suite of technologies focused on the reduction of CO2 emissions, has gained significant momentum in recent years.
In Brazil, several Carbon Capture and Storage (CCS) initiatives are now under planning, among them the Cabiúnas-São Tomé CCS Pilot Project in Campos Basin. The strategic location of the project, close to the seashore, with an onshore wellhead, offers conditions for efficient carbon capture and storage operations and monitoring technologies evaluation. Technical aspects, including a CO2 injection rate of 0.1 million tons per year, a single vertical injector well, three deviated monitoring wells, and the utilization of a high-permeability (∼1200 millidarcies) sandstone reservoir, underscore the planned project’s technical sophistication. Additionally, the potential storage reservoir, a deep saline aquifer characterized by a salinity level of 68,000 milligrams per liter, provides a good geological setting for the secure and efficient storage of CO2 at an injection depth of approximately 1,300 meters.
The monitoring of CO2 injection plume will be paramount, in order to ensure that it remains confined at the targeted reservoir. In this regard, in addition to the three monitoring wells, a 4D seismic land acquisition system is also expected to be deployed at the project area. Moreover, to optimize the 4D seismic value, the execution of 4D feasibility studies is considered a good approach. In this abstract, a 4D petroelastic modeling feasibility study, performed for the Cabiunas-Sao Tome Pilot Project area, will be presented.
-