Extended Reach Drilling to Maximise Production from a Mature Asset – How Geologists and Drillers Can Work Together

Abstract

This case history details how the implementation of a continuous improvement process, in combination with an extensive pre-drill optimisation engineering effort, allowed an operator to expand the existing drilling envelope and provide a cost-effective means to maximise production by accessing significant attic oil, in a mature shallow TVD offshore field. Reservoir modelling had predicted that a combination of a shrinking gas cap and strong water drive had potentially left a 5m oil column above the original wells, which had been placed in the middle of the oil column, and that there was no longer a drive mechanism to allow this oil to be produced. With no platform slots remaining, existing wells would have to be side-tracked and completed as TAML Level 5 multi-laterals. The shallow sandstone reservoir required sand control, which introduced the major challenge of the wells; the installation of significant lengths of sand screens without the ability to rotate to overcome high drag forces generated in the long laterals. The work completed on this project has led to the re-definition of the ERD drilling envelope. In early 2019 a well was completed to a 4,479.82m departure at 631.99m, an ERD ratio of 7.09/1.

AAPG Datapages/Search and Discovery Article #90354 © 2019 AAPG Asia Pacific Technical Symposium, The Art of Hydrocarbon Prediction: Managing Uncertainties, Bogor, (Greater Jakarta), Indonesia, August 7-8, 2019