Session: 11-02-03 Well Drilling Fluids & Hydraulics

Paper Number: 128597

128597 - Integrity of Drilling Fluid as Primary Barrier for Ccs Wells 

Carbon capture and storage (CCS) has been identified as a part of the solution to the climate crisis, but to play a major role, a massive scale-up is required. This will inevitably lead to a need for drilling wells into existing CO2 storage formations, and with that comes the risk of well control incidents where the influx from the formation into the well is dominated by CO2. The primary barrier in the well is the hydrostatic pressure from the fluid column, and it is of crucial importance that threats to this barrier are understood.

Software tools incorporating mathematical models for hydraulics and flow in the well play an important role in risk assessment related to drilling operations. However, these are mainly designed for petroleum wells, and the understanding of the complex interactions between drilling fluids and CO2 is limited. To evaluate the risk of primary barrier collapse it is of crucial importance that the software tools used can capture the relevant thermodynamics and flow physics. By combining existing hydraulic flow models for drilling and well control operations developed for petroleum wells with new sub-models describing the impact of CO2 on the drilling fluid, such a tool is possible. To achieve accurate models, laboratory experiments covering properties such as solubility, density and flow curves of drilling muds loaded with CO2 are required.

Researchers and industry actors here work together to close knowledge gaps and provide the understanding of the physics involved that is required. We present lab results on drilling fluids loaded with CO2 along with considerations on modelling aspects, from thermodynamical sub-models to integrated hydraulic models and the development of a software tool for use in operations planning and execution, and discussions on how such a tool may contribute to reduce the risks related to primary barrier integrity related to drilling of CO2 infill wells.

Presenting Author: Jan Ole Skogestad SINTEF

Presenting Author Biography: Jan Ole Skogestad is a Research Scientist at SINTEF in Bergen, Norway, working mainly on
mathematical modelling and simulation related to drilling and well operations, but also in cross-disciplinary activities. His projects are motivated by the need for safer, more cost-effective and
greener wells as well as digitalization and automation, both in the oil and gas industry and
within new market areas such as CCS and geothermal energy.

Authors:

Elie N'gouamba SINTEF
Blandine Feneuil SINTEF
Jan Ole Skogestad SINTEF
Harald Linga SINTEF
Gjertrud Skår Equinor
Serge M. Roggeband Shell Global Solutions International B.V.
Jack Nedrum Wild Well Control
Sven Inge Ødegård eDrilling