The stage 2 development of the giant Shah Deniz gas-condensate field (SD2) represents an investment in excess of 45 billion USD and requires the drilling of 26 subsea development wells. Significant well cost reductions may be achieved by minimising the amount of ‘non-productive time’ (NPT) during drilling.
NPT associated with subsurface geological characteristics may be minimised by careful pre-drill well planning, robust subsurface interpretation and data integration, application of learnings from previous Shah Deniz drilling and clear communication of subsurface risks to all parties involved in designing and executing the well. To achieve this, a dedicated team exists to provide an Integrated Subsurface Description (ISD) of the overburden and reservoir section at Shah Deniz.
A three year plan describes the key ISD products designed to influence NPT and contribute towards the safe and efficient drilling of wells. These ISD products include an ‘ever-green’ geological model of the field, with overburden, reservoir and aquifer descriptions, plus 3D models of stress and pore-pressure. Such is the complexity of the pore pressure story at Shah Deniz that this represents one of the biggest risks to safe delivery of the wells required for SD2. Delivery of a detailed overburden ISD is enabled by comprehensive interpretation and integration of all well and seismic data acquired over the past 18 years.
This paper will focus on some of the tools and techniques used to enhance understanding of the overburden geology at Shah Deniz, types of overburden products generated and how they are used in well planning.