Comparative Analysis of Drilling Cost Used for Petroleum Economics in the North Sea, Gulf of Mexico and Niger Delta Regions

Abstract Accurate estimation of extreme wave condition is desired for the rational design of offshore structures, but the estimation results are known to have uncertainty from various sources. The quality and quantity of the available extreme wave data differ among ocean regions since the atmospheric causes of extreme waves are not identical. This paper provides insight into how the different extreme wave behaviors influence the uncertainty of extreme wave estimation at each location. A review of extreme waves in four regions, namely the Gulf of Mexico, North West Pacific, Adriatic Sea, and the North Sea, revealed the difference in data uncertainty, shape parameter, and frequency of occurrence. The likelihood-weighted method was introduced to quantitatively assess the impact of each parameter on the uncertainty of extreme wave analysis. Case study based on representative parameters of the Gulf of Mexico and the North Sea revealed the large epistemic uncertainty for a region dominated by tropical cyclones. The assessment conducted in this paper is unique as it evaluates the epistemic uncertainty inherited in the extreme sample data. When the epistemic uncertainty is large, such as the case illustrated for the Gulf of Mexico, the variance from different approaches may not be significant against the epistemic uncertainty inherited in the sample data.

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Horizontal Installation of TLP Tendons

Volume 1: Offshore Technology ◽

10.1115/omae2012-83013 ◽

2012 ◽

Author(s):

Guang (George) Li ◽

Robert Kipp ◽

Steve Leverette

Keyword(s):

West Africa ◽

Gulf Of Mexico ◽

North Sea ◽

Significant Cost ◽

Bottom Part ◽

The North ◽

The World ◽

Heavy Lift ◽

The North Sea ◽

Foundation Pile

Tension Leg Platforms (TLPs) are ideal supports for dry-tree top tension riser systems because their tendons exhibit high tensile stiffness and significantly reduce the heave, pitch, and roll motions of the platforms. Since the first TLP (Hutton) was installed in the North Sea in 1984, a total of 24 TLPs have been installed throughout the world with 16 of them installed in the Gulf of Mexico. Currently there are new TLP projects proposed in regions off the coast of Malaysia, West Africa, Brazil and Western Australia. Heavy-lift vessels were used to install tendons for most of these TLP’s. Tendon joints were assembled vertically from bottom part to top part. Using a heavy-lift vessel introduces significant cost and schedule challenge to TLP projects, especially ones located in remote regions. A horizontal tendon installation methodology is presented in this paper. This innovative approach involves horizontal assembly of TLP tendon segments on a construction barge. The partially assembled tendon is then incrementally pulled out through a stinger at the barge stern and secured with a hold back clamp so that the next tendon joint can be connected. The process repeats itself until the whole tendon is assembled and deployed. The tendon is then upended to a vertical configuration and connected to a TLP or a foundation pile. In this paper, we examine the alternative equipment and configuration options in the horizontal installation methodology. We outline rationales to select the appropriate options and measures to reduce project cost and risks.

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The Safe and Efficient Development of Offshore Transboundary Hydrocarbons: Best Practices from the North Sea and Their Application to the Gulf of Mexico

10.37419/eenrs.offshoretransboundaryhydrocarbons ◽

2019 ◽

Author(s):

Elise Aldendifer ◽

McKenzie Coe ◽

Taylor Faught ◽

Ian Klein ◽

Peter Kuylen ◽

...

Keyword(s):

United States ◽

Gulf Of Mexico ◽

North Sea ◽

Oil And Gas ◽

The United States ◽

Framework Agreement ◽

The North ◽

The North Sea ◽

Regulatory Regimes ◽

Transboundary Resources

Offshore hydrocarbon resources have been developed for many decades, and with technology improvements, many fields which were once impossible to develop, are now economically and technologically feasible. This has led to a growing difficulty in determining the legislative and regulatory framework for resources that straddle the recognized borders between two states. In this paper, we examine a successful framework agreement governing the transboundary resources between the United Kingdom (“U.K.”) and Norway in the North Sea, and the agreement between the United States and Mexico governing the Gulf of Mexico. Following the 2013 Energy Reform, the Mexican energy sector has been revitalized, leading to greater exploration, development, and production than ever before. This means that in the near future transboundary resources may be licensed for production, bringing the issues highlighted in this paper to the attention of multiple government and international entities. This paper seeks to recommend improvements to the transboundary framework in the Gulf of Mexico based on the successful framework agreement utilized in the North Sea. This paper begins by introducing international law for offshore resources in Part II. Part III discusses the offshore regulatory regimes in the U.K. and Norway, analyzing how the two states have successfully used bilateral agreements to facilitate cooperation regarding effective exploitation and apportionment of costs from cross-boundary offshore oil and gas projects in the North Sea. Part IV discusses the offshore regulatory regimes in the United States and Mexico and analyzes the current transboundary agreement in place for the Gulf of Mexico. Part V compares the transboundary agreement governing the North Sea and the same governing the Gulf of Mexico. We highlight the major differences in the agreements and suggest changes to the Gulf of Mexico agreement based on the successful North Sea agreement. Finally, this paper concludes and provides key policy recommendations to improve the rules and regulations surrounding the exploitation of transboundary hydrocarbons in the Gulf of Mexico.

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