Technology Focus: High-Pressure/High-Temperature Challenges (April 2013)

Abstract

Technology Focus High-pressure/high-temperature (HP/HT) operations are projected to double in well count over the next 6 years. In addition to this steady increase in activity, the conditions in these extreme wells will also become more severe as well depths, pressures, and temperatures also trend higher. In the Norwegian sector of the North Sea, one of the most extreme HP/HT wells in that region has been drilled. As a means of addressing the challenges posed by tight pore-pressure/fracture-gradient windows, managed-pressure-drilling (MPD) technologies were applied to minimize the effects of pressure fluctuations that occur in standard drilling. The MPD technology, the so-called “backpressure” technique, uses the controlled application of surface backpressure when mud circulation stops to replace the incremental equivalent-circulating-density effects present when mud circulation is active. In addition to precise management of the pressure profiles imposed on the formations, this active circulation and pressurization technology increases the accuracy with which unwanted influxes can be detected. Influxes as small as 0.25 bbl can be identified, thereby improving kick-detection capability. In south Louisiana, the largest onshore drilling rig in the world has been drilling the deepest well ever drilled in that state, an accolade that is impressive given the long heritage that Louisiana boasts with regard to HP/HT wells. Several operators are active in this area, with a new state depth record being set by one well reaching a depth of 25,500 ft. Another HP/HT prospect in this area is permitted for a total depth of 29,000 ft. In another part of the world, Malaysia, operators are planning ultra- HP/HT operations with bottomhole static temperatures above 430°F. This includes more than a dozen prospects in peninsular and east Malaysia. This region may prove to be one of the most active areas for HP/HT operations in the near future. HP/HT drilling and completions require careful planning, attention to detail, robust testing and qualification programs, strong quality control, and thorough contingency planning. The ongoing industry successes addressing HP/HT challenges globally are testament to the focus that our industry brings to bear as these challenges are met and addressed. Recommended additional reading at OnePetro: www.onepetro.org. SPE 158851 Testing and Perforating in the HP/HT Deepwater and Ultradeepwater Environment by Curtis Wendler, Halliburton, et al. SPE 154768 Developing Novel Wellbore-Heat-Transfer Strategies for HP/HT Wells by Mohd Amin Shoushtari, Universiti Teknologi Petronas, et al. SPE/IADC 163557 Annular-Pressure-Buildup Analysis and Methodology With Examples From Multifrac Horizontal Wells and HP/HT Reservoirs by Jonathan Bellarby, Canmore Consulting, et al.