Abstract: An Integrated Approach to the Development of the Alba Field in the UK North Sea

Christopher Wilkinson, Kevin Flanagan, David Way

The Alba Field is located in UK Block 16/26, about 200 kilometers off the east coast of Scotland. It is a stratigraphic trap composed of fine to very fine grained sandstone. The depositional model is one of a pre-cut channel situated near the base of the palaeo slope, subsequently filled by pre-sorted sand shed from the shelf and upper slope. The reservoir is encased in hemipelagic shales which form the vertical and lateral seals.

Horizontal wells form a major part of the development plan for Alba. Chevron operates a multi-discipline team system whereby all technical functions are involved from the early stages of planning through drilling to completion of the horizontal well. The objective is the optimization of ultimate hydrocarbon recovery.

Once the initial objectives of a horizontal well are determined, a flexible approach is then adopted throughout the drilling phase when all available geological information is assessed as it is acquired, allowing a change in the well path to take account of the geological section encountered.

Although pilot holes are the preferred method of defining the top of the reservoir, this option is not always cost effective and many of the producing wells are drilled without the benefit of these additional data. The development program utilizes an integrated approach to maximize the information being gathered while drilling the wells in order that the optimum well path can be achieved. The interactive application of the wellsite biostratigraphy, real-time formation evaluation logging while drilling, directional survey and continually updated 3D seismic interpretation result in the wells being geosteered very close to the top of the reservoir, minimizing the amount of potential attic oil.

AAPG Search and Discovery Article #90956©1995 AAPG International Convention and Exposition Meeting, Nice, France