Abstract

Carbonates of the Aptian Shuaiba Formation are important hydrocarbon reservoirs in the Arabian Gulf area. Historically, production has been primarily from fields located along the margins of the Bab Basin, an intrashelf basin that formed during deposition of the Shuaiba. The reservoirs in these fields are progradational packages of platform margin carbonates deposited during the late stages of Shuaiba Platform accumulation. The location of the Bab Basin and the associated productive Shuaiba platform margin trend can be illustrated with an isopach map of the Upper Shuaiba (Figure 1).The Bab Basin is represented by an area of relatively thin, basinal Upper Shuaiba carbonates. An additional area of thin basinal Upper Shuaiba carbonates is located to the west of the Bab Basin and marks the western margin of the Shuaiba Platform. A third area containing a thin Upper Shuaiba section is located to the north of the Bab Basin. This area is often interpreted as an extension of the Bab Basin. However, detailed sequence stratigraphic analysis by Qatar Petroleum and ExxonMobil indicates this area was not a basin, but rather was the result of uplift and erosion that truncates the Shuaiba Platform section. This truncation of the Shuaiba Platform is important as it sets up a new play trend within the interior of the Shuaiba Platform far from the traditional productive trend of platform margin carbonates surrounding the Bab Basin to the south.

A detailed sequence stratigraphic analysis of the Shuaiba reveals a complex internal stratigraphy consisting of relatively thick platform carbonates that thin rapidly into the adjacent basins. Superimposed upon this complex internal stratigraphy is the additional complication of uplift and erosion that has beveled much of the platform section to the north. Regionally the top of the Shuaiba is a recognized unconformity marked by widespread exposure. However, this study further documents truncation of section at the unconformity.

This content is only available via PDF.
You can access this article if you purchase or spend a download.