Survey Mgmt to Optimize Landing in Deep Offshore Reservoir

Objective was to improve wellbore position and uncertainty from offset wells to enable the last well of the campaign to enter in the reservoir at the exact top of the structure, behind a fault.

The final purpose was to ensure the optimum in term of reserves and secure 90% of potential reserves of this well without adding any risk or operational time nor jeopardizing wellbore positioning and collision avoidance to a challenging trajectory context (ERD 2 with reduced target 25 x 50 m at ~7800m MD/RT).

• Offset Well Data post-processing.
• Recovery and processing of existing geomagnetic data acquired during the geophysical campaign.
• Lateral positioning correction including the combination of data processing of geomagnetic IFR surveys and Multi Station Analysis correction.
• Vertical repositioning with BHA sag correction was applied with scrutinous assessment of residual sag uncertainty and detailed analysis of continuous survey data.

Offset wells review enhanced the geologic context understanding with 5% consequence in term of oil layer thickness for this well.

Meet well objectives without adding any risk or operational time nor jeopardizing wellbore positioning and collision avoidance.

The uncertainty was reduced by up to 50 to 60%.

The bottom hole location was actually moved by 30m laterally and 3m vertically.

The operator’s choice of valuing the available information to enhance their asset through post processing was a very interesting way to optimize the past efforts put in wellbore positioning to face the economically constrained environment.