The Wandoo Development - Continuous Innovation In Australia
Authors: Goodacre Jack 
Published: October 2008

INTRODUCTION

The Wandoo Field Development is a benchmark for the offshore industry in terms of content, speed of construction and installation, quality, technology and safety. The go-ahead to develop the Wandoo full field development was given in late 1994. Slightly more than two years later, plateau oil production has been achieved - an outstanding result. Benchmarking for similar projects suggests that the industry norm has been three years. The facility meets all of its design specifications and exceeds many. For example, the facility has proven to be able to produce in excess of 50,000 bbls/day of oil relative to a design capacity of 40,000 bbls/day. New technologies were developed and introduced to the West Australian environment in a number of areas including concrete gravity substructure (CGS) construction and installation, the use of floatover Hideck installation method and the all-horizontal, all geosteered subsurface development. New, Alliance, style contracting strategies were proven to be effective. Performance in each area has set new standards. In terms of safety, the lost time injury frequency rate for the entire project was around 3 LTIs per million man hours, significantly better than the industry norm. There were no hook-up and commissioning injuries, there were no start-up injuries and there were two drilling-related lost time injuries. In terms of local content, Wandoo achieved approximately 70% local content in the construction phase which will increase to 80% over the full lifetime of the Wandoo field, a significant boost to the local industry. This paper covers five broad areas, construction, drilling and completion, and production. An underlying theme in each of these areas is technical excellence, and a focus on outcomes.

FIELD DESCRIPTION

The Wandoo field is approximately 50km off the coast of north-west West Australia (Fig 1). It a fault bounded, 3 way dip, structural trap and has an unusual mix of rock and fluid properties. The reservoir consists of two highly unconsolidated sands, termed Unit B and Unit A. Unit B is in the basal part of the reservoir and consists of fine grained quartz sands with some glauconite. It averages 35m in thickness. Core porosity commonly exceeds 35% and horizontal permeability measurements from special core analyses within Unit B vary from 2,000 mD in glauconitic intervals to more than 15,000 mD in clean quartz sections. The high quality of the Unit B reservoir is largely due to the relative absence of pore-filling clays and matrix material and uniform size distribution. Unit B contains approximately 15% glauconite. The reservoir is predominantly composed of fine-grained, well-sorted, high spherical and rounded quartz grains. The only cement present is in the form of localised sideritic bands that may create permeability barriers within the reservoir. Unit A, which overlies Unit B, has been observed to be up to 12m thick and is composed of glauconitic sandstone grading to greensand. Typically it contains up to 50% glauconite. Porosity and permeability in Unit 'A' are lower than those for Unit B, with average porosities of 25% and permeabilities in the range 500 to 3000mD. Unit A contains a lower quality reservoir that improves with increasing depth.