BROWNFIELD REDEVELOPMENT - NATIONAL OIL CORPORATION
OVERVIEW
An optimised Field Re-Development Plan (FRD) needed to be implemented for an 80-year-old, 900+ well oil and gas Brownfield where large volumes of legacy digital and unindexed analogue data existed. Only 15% of historical production and injection data and 20% of the well log data was available in digital form. Optimal EOR could only be done if all the historical production could be captured & databased and a new subsurface static model was created using all the well log data.
APPROACH
HDS GeoSCOPE was used to index and database all existing structured & unstructured digital data and catalogues, establish the actual data coverage and identify the gaps within it.
Data mining was then used on the data to [wally – enter a bit about why and for what data mining was used]. From the gap analysis a data capture project was launched to scan and key-in all of the missing production and injection data, well completion records and well logs.
DELIVERABLES
Over 3,000 analogue well scanned imaged were fully catalogued with full header, run and mud parameters and 12,500 individual curve records identified and logging intervals captured. Where possible the digital data was validated against analogue records.
Gap analysis was performed to identify missing data. As result, an HDS team was sent to the asset field data archive where additional well logs, well files and production/injection history reports were scanned.
210,000+ pages of well file information were captured, covering some 840 wells. Amongst this data there was over 130,000 months of production and injection data covering about 650 wells added to the field knowledge base.
70,000 monthly production and injection records were captured for selected wells and entered into OFM ready format, so as to complete the field production history.
In addition, 2.25 million curve metres of well log curve data was digitized off the analogue scanned logs to complete the well curve data coverage prior to full compositing, despiking, editing and splicing of the well data.
Specialized SP curve normalisation and baseline shifts were applied as well as dynamic depth adjustments where necessary to make the well curve data “petrophysics evaluation ready”. This was done for 435 wells (448 individual boreholes), with full auditability of processes applied and the provenance of each data value delivered.
A completed well production/injection database that was merged with the existing OFM database.
A completed RAW & MASTER petrophysical well log database with full audit trail of data provenance and edits performed. Formation Evaluation was performed on about 100 extension wells in support of the Company petrophysicists.
VALUE ADDED
A significant reduction in the data gaps ensured that the subsequent subsurface model and production history matches were much improved.