The Upper Jurassic Arab Formation in the Arabian Peninsula, the most prolific oil-bearing interval of the world, is a succession of interbedded thick carbonates and evaporites that are defined stratigraphically upsection as the Arab-D, Arab-C, Arab-B, and Arab-A. The Arab-D reservoir is the main reservoir in Khurais field, one of the largest onshore oil fields of the Kingdom of Saudi Arabia.
In Khurais field, the Arab-D reservoir is composed of the overlying evaporitic Arab-D Member of the Arab Formation and the underlying upper part of the Jubaila Formation. It contains 11 lithofacies, listed from deepest to shallowest: (1) hardground-capped skeletal wackestone and lime mudstone; (2) intraclast floatstone and rudstone; (3) pelletal wackestone and packstone; (4) stromatoporoid wackestone, packstone, and floatstone; (5) Cladocoropsis wackestone, packstone, and floatstone; (6) Clypeina and Thaumatoporella wackestone and packstone; (7) peloidal packstone and grainstone; (8) ooid grainstone; (9) crypt-microbial laminites; (10) evaporites; and (11) stratigraphically reoccurring dolomite.
The Arab-D reservoir lithofacies succession represents shallowing-upward deposition, which, from deepest to shallowest, reflects the following depositional environments: offshore submarine turbidity fans (lithofacies 1 and 2); lower shoreface settings (lithofacies 3); stromatoporoid reef (lithofacies 4); lagoon (lithofacies 5 and 6); shallow subtidal settings (lithofacies 7 and 8); peritidal settings (lithofacies 9); and sabkhas and salinas (lithofacies 10). The depositional succession of the reservoir represents a prograding, shallow-marine, reef-rimmed carbonate shelf that was subjected to common storm abrasion, which triggered turbidites.
Added on 30 June, 2013
Renaissance era: Geoscience research – often more practical than theoretical – is enjoying a strong revival.
Added on 01 July, 2010
Explorer Director’s Corner
Last month I had the privilege of traveling to the Middle East with AAPG President Lee Krystinik.
Added on 01 February, 2014
Explorer Division Column EMD
Over the past year or so we have observed strong evidence that nuclear power is into a new expansion period.
Added on 01 November, 2014
This year, URTeC has added an enhanced preview of “Coming Attractions.” In addition to looking at established plays, URTeC will provide significant information about emerging unconventional resource possibilities in North America and around the world.
Added on 01 July, 2014
Three new research facilities divide their focus between downstream and upstream technology for Aramco Services.
Added on 01 November, 2013
An added dimension: 3-D seismic data is an essential ingredient in operators’ efforts to understand the risks and nuances of shale plays.
Added on 01 March, 2012
Explorer Foundation Update
It has a new name, a new energy and a new lineup of experts, all primed to spread geoscience knowledge around the world. “It” is AAPG’s newly named Global Distinguished Lecture Program – emphasis on the “global” – which dates back to 1941 but continues to be the Association’s flagship initiative for offering the latest in geologic science to AAPG affiliated geological societies and universities.
Added on 01 October, 2014
Explorer Historical Highlight
The history of oil in the Middle East is essentially a story of giant oil fields (each containing over 500 million barrels).
Added on 01 June, 2011
Explorer Policy Watch
It’s common knowledge, and it’s wrong. The top suppliers of crude oil to the United States are Canada and Mexico.
Added on 01 September, 2010