Advances in Horizontal-Oriented Perforating Optimize Perforation Efficiency andProduction While Maintaining Borehole Stability

摘要

A major operator in the North Sea put one of their fields onstream in the autumn of 1988. Since then, over 1.7 billionbarrels of oil have been produced, reaching a peak of morethan 500,000 BOPD. Today, an estimated 0.9 billion barrelsof oil remain to be recovered from the field; however,production has fallen to less than 400,000 BOPD and theoperator is facing tremendous challenges to increaseproduction.New technologies, such as horizontal drilling and horizontaloriented perforating have helped increase production.Drilling in a water depth of 109 m of water, the operatorwanted to optimize production from a 2246-m horizontal wellsection by reducing the risk of future sand production andselecting the most effective perforation coverage.Perforating in highly deviated or horizontal wells presents anyservice company with a serious technical challenge.Attempting to maintain wellbore and perforation tunnelstability by perforating in the direction of maximum stresscompounds the complexity of the perforating job. Ensuringthat orientation remains valid while navigating through severedoglegs requires detailed pre-job design planning supported byapplicable research data.This paper discusses advances in horizontal orientedperforating in long horizontal sections designed to optimizeperforation efficiency and production. The techniques andresults discussed are applicable to any horizontal or highlydeviated well where orientation of charges to maintainwellbore stability is critical. New developments to navigatethrough severe doglegs and maintain orientation aresignificant contributions to perforation technology. Some of the results and experiences encountered while performing anoriented perforating job in a 2246-m horizontal section of theNorth Sea well are also discussed in this paper. A worldrecord was set by perforating a net of 1496 m of the horizontalsection in a single trip with orientation successfully verified.Additional discussion on the testing and research thatpreceded the job is presented.As demonstrated in positive results from the North Sea well,perforating with oriented charges in horizontal sections willplay a key role in the future to assist operators increase andoptimize production from new or declining fields.