Sequence stratigraphy of the petroliferous Dariyan Formation (Aptian) in Qeshm Island and offshore (southern Iran)

Abstract

After sea level rises during the Early Cretaceous, upper parts of the Khami Group sediments (Fahliyan, Gadvan, and Dariyan Formations) deposited over Jurassic sediments. The Lower Cretaceous (Aptian) Dariyan Formation (equivalent to the Shu'aiba Formation and Hawar Member of the Arabian Plate) carbonates, which have hydrocarbon reservoir potential, form the uppermost portion of the Khami Group that unconformably overlays the Gadvan Formation and was unconformably covered by the Kazhdumi Formation and Burgan sandstones. Detailed paleontological, sedimentological, and well log analysis were performed on seven wells from Qeshm Island and offshore in order to analyze the sequence stratigraphy of this interval and correlate with other studies of the Dariyan Formation in this region. According to this study, the Dariyan Formation contains 14 carbonate lithofacies, which deposited on a ramp system that deepened in both directions (NE-wells 5, 6 and SW-wells 1, 2). Sequence stratigraphy led to recognition of 5 Aptian third-order sequences toward the Bab Basin (SW-well 1) and 4 Aptian third-order sequences toward Qeshm Island (NE-wells 5 and 6) so these areas show higher gamma on the gamma ray logs and probably have higher source rock potential. Other wells (wells 2-4 and 7) mainly deposited in shallower ramp systems and contain 3 Aptian third-order sequences. On the other hand, rudstone and boundstone lithofacies of studied wells have higher reservoir potential and were deposited during Apt 3 and Apt 4 sequences of the Arabian Plate. The Dariyan Formation in Qeshm Island (well 6) and adjacent well (well 5) was deposited in an intrashelf basin that should be classified as a new intrashelf basin in future Aptian paleogeographic maps. We interpret that salt-related differential subsidence, crustal warping, and reactivation of basement faults of the Arabian Plate boundary were responsible for the creation of the intrashelf basin in the Qeshm area.

Larger benthic and planktonic biostratigraphy and facies of Albian sediments in Coastal Fars Zone (Zagros area, south‐west Iran)

“…This microfacies is characterized by a grainstone texture (Figure 10e). Mansouri-Daneshvar et al (2015) attributed the same microfacies as a back-reef margin of organic build ups of the sedimentary basin, as also noted by Vilas et al (1995). Microfacies 4 is recognizable in the upper portion of the studied section (7 m in thickness).…”

Boundaries Determination in Potential Field Anomaly Utilizing Analytical Signal Filtering and its Vertical Derivative in Qeshm Island SE Iran

“…Generally, Limestone is the dominant lithology of the main reservoirs in this area and its surroundings. The major oil reservoirs are the members of the Sarvak formation (Cenomanian-Turonian), especially the Mishrif member (Upper Sarvak) (Mansouri-Daneshvar et al, 2015;Saadatinejad & Hassani, 2013). Qeshm island on Iran's southern coast is the largest island of the Persian Gulf by area.…”

Depositional sequence interpretation using seismic and well data of offshore Central Sumatra Basin

“…The success of hydrocarbon exploration depends on understanding the subsurface geology of exploration fields [1]. Sequence stratigraphy studies have a significant role in exploratory studies to determine the continuity of petroleum system [2]. Sedimentary deposits from Pematang Formation to Petani Formation are predominantly formed in marine depositional environments (Figure 1a) [3].…”