The microporous rock types in Upper Shuaiba are low permeability (~ 1mD) rocks occurring in thin (2-5 m) formations within the extensive Upper Shuaiba carbonate formations in Lekhwair. These microporous rocks constitute a significant volume of hydrocarbon in-place. Unlike the higher quality rudist-rich and grainstone rock types, appraisal pilots in the microporous areas have shown poor performance with waterflood development, which is the preferred development concept in the entire Lekhwair field. Two work streams are active in parallel to identify a technically and commercially feasible development option: Phase 1, technology trials to enable a successful waterflood implementation, and Phase 2, further studies to screen the potential of enhanced oil recovery (EOR) techniques and other light tight oil development.
The technology trial work stream, initially considered four initiatives targeting injectivity improvement. To date, trials are complete for abrasive jetting and designer acid stimulation, early results are available for Directional Acid Jetting, and evaluation of Fracture Aligned Sweep Technology (FAST) is ongoing with hydraulic fracturing evaluation accelerated to Phase 1 due to synergies with the FAST evaluation. Trial results to date:
Abrasive Jetting: 7 trials complete, limited success in improving injectivity.
Designer Acid Stimulation: 1 trial complete, no to limited injectivity improvement
Directional Acid Jetting: implemented in 3 wells, injectivity improvement in early injection
FAST: trial planning ongoing
Hydraulic Fracturing: trial planning ongoing
This paper discusses the encouraging results and learnings to date with regard to these new technology trials, and the early screening results for the implementation of gas injection as an alternate recovery mechanism.