--> Abstract: Lateral Jetting of Wellbores, John Durkee, #90097 (2009)

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Lateral Jetting of Wellbores

John Durkee1,   Jerry Green2

1Well Enhancement Services,  2Well Enhancement Services

The process of jetting drain holes into oil and gas reservoirs to improve daily production rates has resulted in significant initial and sustained increases over the rate before reworking. Wells with high initial production rates, oil/water ratios and rapid declines are prime candidates for repressurization. Settled production rates are a function of reservoir pressure. Operational and economic successes have been demonstrated in sandstone, limestone, dolomite, shale and coal bed reservoirs. Of the wells that were economic successes, the wells with the largest present-value increase were usually those worked over early in their productive life.

In a case study, two new wells were drilled in the fourth quarter of 2008 and prepared open hole, specifically to be completed with the jetting process. Peak porosity in the exposed limestone in these wells was 6% & 10% respectively. The wells were bailed dry with no measurable fluid entry, then jetted with 15% HCl, followed by a water flush. Production swab tests indicated fifty and seventy barrels of oil per day (bopd) respectively. After thirty days’ production the first of these wells is producing twelve bopd and thirty-five barrels of water per day.

In practice, approximately seventy-five percent of attempted laterals reach the target length of three hundred feet. Various subsurface conditions like fracturing, faulting, or highly deviated formations could be the cause of early termination, but in many cases allowing the jet to cut on the barrier will permit the lateral to cross the boundary into a new reservoir compartment and reach the desired length.

 

 

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