The Impact of Compressed Natural Gas Shipping upon Offshore Gas Development

Abstract

This paper introduces the marine gas transport technology under development by EnerSea Transport LLC as it is being incorporated in a new ship concept. The new Compressed Natural Gas (CNG) transport system and ship design have global applicability and allow a new perspective on remote offshore oil and gas development. The paper explains how key considerations and challenges have been reflected in the design of the new ship and how that new gas ship concept opens a new world of maritime and offshore field development opportunities. Introduction Industry is beginning to recognize that technology allowing marine transport of Compressed Natural Gas (CNG) provides flexibility that changes the economics for marginal fields. This is especially true for gas fields in ultra-deep waters or locations remote from suitable markets. A new solution for handling, storing, and transporting gas is making many operators appreciate the breakthrough potential for marine CNG as a means to commercialize stranded gas in remote reservoirs around the world. A new class of ocean-going vessels and gas handling facilities will play key roles. Through its Maritime Work Program, EnerSea Transport LLC and its strategic partners have developed an advanced ship design employing the proprietary Volume Optimized TRANsport and Storage (VOTRANS?) gas handling concepts. EnerSea Transport selected the world's leading maritime companies and a top energy company to form a team of unmatched engineering and project development capabilities. The leadership of EnerSea's team includes Kawasaki Kisen Kaisha, Ltd ("K"-Line) and Hyundai Heavy Industries (HHI) with strong professional support from Paragon Engineering Services Inc., the naval architects of Alan C. McClure Associates Inc., and ABS Consulting. This team has worked together with the American Bureau of Shipping (ABS) over the past year to create and verify a safe, practical ship design that provides the basis for launching the world's first fleet for CNG marine transport, opening the way for a new maritime energy transport industry. CNG marine transport allows emerging, energy-hungry markets around the globe to access gas reserves that would otherwise remain stranded. As compared to other solutions for de-stranding of gas reserves (LNG & GTL technologies), the shipping of CNG offers a solution that significantly limits the wastage of gas resources that are needed in the emerging markets and the amount of captive investment required of operators. Such value-adding features make this breakthrough technology and the new class of ships attractive to gas and power players on a global scale.

Delivering Offshore Gas to Regional Mid-Markets: Assessing the Comparative Merits of Floating LNG and CNG Transport Routes

“…Product preparation for storage and export Requires only gas compression to the required storage pressure (Sea NG concept) or gas compression with low level refrigeration (for the Enersea Concept) (8) Requires deep refrigeration scheme for liquefaction of the gas at -162ºC. Any liquids generation needs to be accommodated in FCNG unit, and arrangements are required to ship out these liquids which detract from the simplicity of the CNG concept NGLs need to be fractionated out to meet typical limits on Butane content.…”