Advanced Reservoir and Seal Characterization at the Kemper Storage Site

Abstract

Robust reservoir and seal characterization is critical for determining the capacity and risk associated with long-term carbon storage. The ideal approach for lowering storage site uncertainty is to analyze local, high-density subsurface data. At the Kemper storage site, there are few available subsurface data and the coring program was challenged by the friability of the lithology. To maximize the recoverable data from limited wells and core, we have developed an analytical program that will determine properties of multi-phase flow in distinct reservoir and sealing lithologies using core from the MCP10-4#1 well. This CarbonSAFE project is supported by the USDOE-NETL and MPC, and is managed by the Southern States Energy Board. Technical Support is provided by Southern Company Services.

Multi-phase fluid flow experiments will be performed on three lithofacies from the Paluxy Formation: a cross-bedded sand that is the most prominent facies (5,115.5-5,116.8’), a partially bioturbated massive sand (5059.2-5060.4’) and a cobble-rich lag deposit (5,132.3-5,133.3’). The samples recorded gamma readings of between 22-30 gAPI and with formation resistivity that is generally around 0.2 ohm.m. These data suggest that the sample interval in the Paluxy Formation contains relatively clean sands with saline brines. Samples will be analyzed for relative permeability coupled with real-time CT scan for determining displacement and trapping responses, capillary pressures, wettability and interfacial tension properties. At this time, experiments have just begun.

Two samples from the marine Tuscaloosa Formation were selected for advanced seal characterization. Sealing properties will be determined using capillary displacement pressure tests. The "minimum capillary displacement pressure" is determined by saturating a core plug with brine, draining the brine by imposing a gas pressure difference greater than the breakthrough pressure, then allowing it to reimbibe until the equilibrium pressure difference is established. The dependence of the effective permeability to gas on the pressure difference during this sequence provides data with which the time dependence of CO₂ seepage from a through a seal can be estimated, should the breakthrough pressure of the caprock be exceeded. This contributes to an informed decision regarding the need for intervention to manage the seepage, by carbon dioxide and brine withdrawal, injection control, mineralization, or other means.

AAPG Datapages/Search and Discovery Article #90323 ©2018 AAPG Annual Convention and Exhibition, Salt Lake City, Utah, May 20-23, 2018