Radhuma, Rus and Dammam Section of Kuwait, Sequence Stratigraphic Analysis

A. Youssef¹

Abstract

A high resolution biostratigraphical and paleoenvironmental investigations have been integrated with sedimentology and wireline log data to establish a biostratigraphically constrained sequence stratigraphic framework of the study section. The biostratigraphic analysis of over 1000 core and cutting samples from 15 wells, distributed all over Kuwait, has recognized ten 3rd order sequences over the Radhuma, Rus and Dammam formations. The study identified five 3rd order sequences in Radhuma, two 3rd order sequences in Rus and three 3rd order sequences in Dammam. All the identified sequences are composed of sequence boundary (SB), transgressive systems tract (TST), bio-based maximum flooding surface (MFS) and highstand systems tract (HST) and all could be correlated regionally. The Radhuma Formation is mainly composed of fine to coarse grained dolostone to dolomitic limestone with two intervals of anhydrite intercalated with dolostone, limestone and shales in the upper part of the formation. The Rus Formation is composed of anhydrite with intercalations of dolostones and dolomitic limestone. A major unconformity between Rus and Dammam formations is manifested over the crestal part of Burgan Arch. The Dammam Formation is mainly composed of limestone, dolomitic limestone, dolostone and shale. The basal part is composed of relatively deep marine facies which contains the 2nd order MFS of this sequence. The RAD100_MFS is recorded at the lower part of this sequence. It is identified in MU-C well at 3900’, where common ghosts of keeled Globorotalia spp have been found. The RAD200_MFS is best identified in MU-C well within the interval 3660 – 3730’ where it contains common planktonic foraminifera. It is recorded also in well SA-A at 3700 –40’, where it is composed of milky white, chalky limestone and contains rare - common benthic forms and rare small gastropods. It is also recorded in well BU-A at 4680’ dolomitic limestone containing rare to common dolomitized benthic forms. The RAD300_MFS is recorded at depth 2478.6, in UG-A, where it is composed of chalky limestone. It is indicated by the common foraminiferal planktonics such as; keeled Globorotalia spp and Acarinina meckanni indicating Paleocene age, other benthic forms are recorded as well. Based on the wireline logs this MFS can be defined between the second Eocene anhydrite and the RL (Rotalia / Lokchartia) marker This MFS is correlatable with the 2nd order Pg10 MFS (58 Ma) described in previous works.

AAPG Search and Discovery Article #90188 ©GEO-2014, 11th Middle East Geosciences Conference and Exhibition, 10-12 March 2014, Manama, Bahrain