Steps Towards a Comprehensive Reeled Tube Drilling System

Abstract

The oil industry is facing the challenges of reduced margins with respect to optimization of mature field and development of marginal discoveries. In this context conventional approaches are reaching their limits and a step change is required. The first oilwells were drilled using the cable tool method. The Rotary drilling revolution was introduced in 1901 and became firmly established in 1920. Since then the industry has been dominated by the reign of the 30 ft. joint. Replacing jointed pipes by continuous reeled tubes could indeed become the next step change. A visionary Reeled System (RS) including drilling umbilicals, casing, tubing and pipelines could improve the economics of hydrocarbon development projects. RS could reduce costs, enhance quality, broaden technical abilities and improve well productivity. An all around RS does not exist and the intention is not to build one from scratch. However, Coiled Tubing (CT) is presently the nearest thing to the reeled tube vision. Recent experience prove CT can be used for drilling, completions and flowlines and its envelope of application is rapidly expanding. It is proposed to build a global alternative to jointed pipes by gradually improving the technical abilities of the existing CT system. Pieces of the giant jigsaw puzzle are already in place. Others are still at the conceptual stage while some are still barely visible. Reeled System Technology (RST) will evolve at its own pace driven by market forces, technology innovation and most importantly attitude change. Rather than a mere technical improvement this technology authorizes new strategies for hydrocarbon exploitation. Introduction Oilfield technology has developed significantly since the turn of the century but well technology is still dominated by the rotary technique. Today this technique is capable of routinely drilling wells to depths of 7500 m and exceptionally to depths greater than 13 500 m. Highly deviated or horizontal extended reach wells can penetrate hydrocarbon reservoirs at distances up to 7200 m from the surface location. To achieve these depths and deviations requires large conventional drilling installations. Such operations consume large quantities of expensive equipment and in .the face of low oil prices and rising costs operators have examined other technologies. Slimhole drilling - a relatively new technology - can yield substantial savings compared to conventional operations, by drilling "slimmed down wells with final diameters smaller than 4 3/4-in. These improvements have so far managed to contain cost levels in increasingly difficult conditions, but they are facing a tough test in today's economic environment. It's a fact of life that, as fields get older, production tends to decline. More water is produced, and more compression and more artificial lift is needed. New fields tend to be deeper, in tighter rock, with higher pressures and temperatures. Often they are smaller and in more complex settings. In this context, the oil industry is challenged to identify strategies for maximizing the value of new and existing reserves. Cost cutting is applied across the board. Organizations are slimmed down, projects and investments are critically reviewed, procurements and contracting practices are undergoing major revisions and benchmarking is becoming a must. Cost reduction is only one side of the coin. P. 257