Integrating Formation Micro Imager and Sonic Stoneley Waves for Fracture Characterization of the Eocene Carbonate Reservoir; Gulf of Suez Area, Egypt
AbuElFotoh, Ahmed M.*1; Emam, Mahmoud 1; Juandi, Dedi 1
(1) Consulting Services, Schlumberger, Cairo, Egypt.
The studied Eocene carbonate reservoirs of Gulf of Suez area are primarily fractured and characterized with swarms of high angle fractures and fracture corridors. All these fractures are faulting related, sited in a very complicated structure envelop within the Gulf of Suez rift setting. Thus, Fracture characterization of such reservoirs is extremely important to understand the reservoir behavior and hence assigning the best completion intervals for the producing wells.
The studied well was drilled at the peak of an anticline structure created by fault propagating fold of a normal fault that located nearby the well. In this paper, a workflow of integrating formation micro imager log, Stoneley waves and petrophysical analysis was employed. Formation micro imager provided the fracture classification, orientation and fracture attributes (fracture density, fracture aperture and fracture porosity). Moreover, the high resolution formation imager was utilized to capture and quantify the different scales of diagenetic dissolution vugs and cavities developed in such carbonate facies. A combination of Stoneley waves attenuation and acoustic anisotropy analysis were engaged to differentiate the open fractures from the cemented ones therefore, quantify the effectiveness of these fractures as fluid conduit. In addition to some information about the insitu stress envelop affecting the studied reservoir. Other petrophysical interpretations were established using the elemental spectroscopy data with conventional logs to provide a comprehensive petrophysical formation evaluation of lithology, porosity, permeability and water saturation.
The study brought out that highest average fracture density in Layer-A and B around 2.2 fractures/foot and 1.5 fractures/foot in Layer-C. These fractures were proved to be good fluid passage. Based on the study results, the two layers A and B were recommended to be tested. The Drill Stem Test results proved the higher productivity than layer C which confirms the outcome of our integrated study.
AAPG Search and Discovery Article #90141©2012, GEO-2012, 10th Middle East Geosciences Conference and Exhibition, 4-7 March 2012, Manama, Bahrain