As the oil and gas industry pushes into deeper water, more-complex environments, and frontier unproduced areas, the technical and nontechnical risks related to appraisal and development of deepwater projects are likely to continue to increase substantially.
While the technical challenges related to deepwater developments are significant—perhaps more significant and critical to the venture success—it is important that the nontechnical aspects of managing a new development in a frontier area be incorporated at the onset.
After the successful discoveries in deepwater basins across the globe in west Africa, the North Sea, the Gulf of Mexico, Brazil, and elsewhere, operators are using the lessons learned and technologies developed in these fields to explore other frontier deepwater fields.
The exploration in deep water becomes complex on the basis of various factors, such as water depth, geological formations, weather conditions, lack of oilfield infrastructure, and material and tools availability.
The definition of deep water may vary with operators, but one definition of a deepwater field is any area of exploration where the water depth is greater than 150 m and there is a subsea blowout preventer. NORSOK defines deep water as water depth in excess of 600 m. Deep water may range from 600 to 3000 m, and ultradeep water is anything deeper than that.
Deepwater operations create several additional challenges that need to be addressed in the design phase. Some of these, such as low temperatures at seabed, shallow flow hazards, and possible hydrates, are problems that are most commonly associated with deepwater operations. Other challenges, such as low fracture gradients and proper mud removal for cement placement and zonal isolation, are also common in nondeepwater environments; however, these become more complex, more significant, and more difficult to manage in deep water.
There is no question that deepwater production will play a very important part in meeting the world’s future energy demand. The challenge for the oil and gas industry is to meet this demand safely, efficiently, and profitably.
This is not an easy challenge in deep water, given the limited margin for error. The technical complexity and multibillion-dollar development costs require a robust development strategy that allows a project to deliver the promised value within the constraints of time.
Recommended Additional Reading
OTC 25135 Deepwater Development Strategy by Martijn Dekker, Shell, et al.
OTC 25443 50 Reservoirs, 48 Well Slots, and Two TLPs—Maximizing Recovery From the Deepwater Prolific Mars Field by Derek Newberry, Shell
SPE 169245 Overcoming Ultradeepwater Cementing Challenges in the Caribbean by N. Gupta, Schlumberger, et al.
SPE 170286 A Novel Approach in Locating Single Loss Zone During Deepwater Drilling With Distributed-Temperature Measurement by Yuanhang Chen, The University of Tulsa, et al.
Morten Iversen, SPE, graduated from the University of Stavanger in 1981 and has worked throughout the world for different operators and for several service companies. He currently works for BG in Trinidad and Tobago as the completion team lead responsible for completion, interventions, and well integrity for all BG wells in Trinidad and Tobago. Iversen holds several patents, including for a tubing-conveyed perforating-shot detection system and a deepwater-blowout-preventer system for riserless light well intervention (RLWI). He has worked on implementing the RLWI technology from its infancy in the late 1980s and later as a global subsea adviser for Welltec, optimizing the use of RLWI technology to increase well recovery in subsea wells. Iversen serves on the JPT Editorial Committee.