Drilling Deep in Deep Water: What It Takes to Drill Past 30,000 ft

Abstract

In 1919 the world record for the deepest well was broken by the Hope natural gas company with a total depth (TD) of 7,579 ft. Although it took over 3 years to reach TD, only 325 days were spent actually drilling. Today in deepwater operations, the water depth alone can exceed this record, and operators have drilled past 30,000 ft in just 4 or 5 months. Technology and procedures have evolved extensively as operations that appeared impossible a decade ago are now considered routine. Today, operators are being pushed more than before, not just to explore deeper prospects, but also to get there efficiently. The future of the industry depends on it. Now there are new questions the industry is asking about deep water: What is different about drilling deep in deepwater operations? What does it actually take to drill the deepest wells in the world today? Currently, there are only a handful of personnel with the knowledge and experience to execute these wells. This paper will discuss the challenges of planning and drilling directional wells in excess of 30,000 ft true vertical depth (TVD) and will also look at lessons from some of the major deepwater Gulf of Mexico (GoM) operations that have successfully drilled wells beyond this mark and are continuing to push the envelope further. These wells have held, at one time or another, records for deepest wells drilled in many categories in recent years. IntroductionMany of the deepest wells in the world have been drilled in the GoM, and many have been in deep water. Fig. 1 illustrates the trends in total TVD of the wells for the GoM. Fig. 2 illustrates the trend in increasing water depths with time for wells in the GoM. The direction that the industry is heading in is deeper: deeper water and deeper wells. The technology exists to take us there. However, there are critical factors to consider when planning these wells.

Research on the Influence of Deep-Water Drilling Risers on Drillstring Motion Trajectory and Vibration Characteristics

“…Deep-water drilling risers will have a significant impact on drillstring vibration [1,2], which is a crucial factor affecting drilling efficiency. The high levels of shock and vibration experienced during deep water drilling in Brazil [3][4][5] and Mexico [6][7][8] have severely affected the rate of penetration (ROP). Moreover, the presence of complex-coupled vibrations such as stick-slip and whirling phenomena poses great challenges to deep water drilling operations.…”