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Saudi Aramco's first deepwater exploration well targeted a sub-salt Miocene syn-rift section located in over 2,000 ft of water and beneath 9,000 ft of halite and evaporites. Offset well information from previous shallow exploration wells was limited; therefore, calibration for pre-drill pore pressure and fracture gradient prediction (PPFG) was performed using a single shallow water well completed two months prior to spuding the well. Pre-drill PPFG predictions presented a very high degree of uncertainty, which translated into uncertainty in well design and mud weight planning. Pre-drill pore pressure prediction relied on seismic velocities extracted from a wide azimuth 3D survey and used Residual Normal Move Out (RNMO) and seismic inversion to extract velocities that were presumed to represent shale velocities. Real-time pore pressure monitoring was based on a comprehensive program that included logging while drilling (LWD), multiple look-ahead vertical seismic profiles (VSPs), velocity model updating and rapid remigration (pre-stack depth migration) around the wellbore to produce simultaneous improvements in imaging and depth estimates that were tied back to an evolving geological pore pressure model. Significant differences between the pre-drill pore pressure model and measured well pressures highlight the critical importance of the pre-stack depth migration (PSDM) velocity model and the necessity to be able to modify the seismic velocity model and calculated pore pressures in real time to provide accurate information to drilling operations. An integrated team of technical professionals from nine separate departments was required to successfully carry out this project, which resulted in the successful drilling of a deepwater well in a high overpressure -low fracture gradient environment with minimal operational downtime. Geological Setting and StratigraphyOpening of the Northern Red Sea rift began approximately 25 MaBP as the Arabian platform began to move east (25-15 MaBP) then northeast (15-0 MaBP) relative to the African craton. Initiation of the Northern Red Sea rift triggered the onset of syn-rift deposition into a series of graben and half graben basins that continues to present day. The deepwater (beyond 1,000 ft water depth) syn-rift stratigraphy consists of Oligo-Miocene sediments up to 21,000 ft thick deposited under varied depositional environments and settings that are related to the macro tectonic evolution of the rift system. In terms of

Background This study was conducted to evaluate our local experiences of adjunctive mechanical prosthetic wrapping for aortoiliac vascular anastomoses as a prophylactic measure following surgical repair of Behçet’s aortoiliac aneurysms. The goal of prosthetic wrapping to reinforce the vascular anastomoses by mechanical protection to reduce the bleeding complications, and consequently pseudoaneurysm formation. This was aided by the administration of pre- and postoperative immunosuppressive therapy as an adjuvant treatment. Methods A seven-year retrospective study was conducted between January 2006 and December 2012, retrieving data of patients with Behçet’s aortoiliac aneurysms. All patients underwent open surgical repair using a heparin-bonded synthetic Dacron® graft. Data for all patients were retrieved and analyzed for diagnostic procedures, graft selection, as well as, different methods of surgical repair. Graft-related complications such as anastomotic pseudoaneurysms, occlusion, and thrombosis were also reported. Results Sixteen patients were recruited in this study. There were  11 (69%) males and 5 (31%) females with the male to female ratio 2:1. The patients’ age ranged between 25 and 47 years with the mean of 36.4 ± 7.3. All Behçet’s aortic/aortoiliac aneurysms were repaired by the application of heparin-bonded Dacron® tube and bifurcated grafts. The anastomotic wrapping technique was performed for both the proximal and the distal vascular anastomoses. The technical success of aortoiliac aneurysm and wrapping techniques was achieved in 100% of patients. All patients were given pre- and postoperative systemic immunosuppressive therapy. No graft-related complications were reported except for only one anastomotic pseudoaneurysm that developed at one of the right iliac anastomoses, that developed within 24 months after follow up. Conclusions Mechanical prosthetic wrapping for vascular anastomoses in patients with Behçet’s aortic/aortoiliac aneurysms is a feasible, simple, and reliable technique with low morbidity and mortality. It was performed as a prophylactic measure to avoid the development of postoperative anastomotic pseudoaneurysms. It must be performed for all patients with Behçet’s arterial aneurysms whenever possible. Furthermore, the supplemental administration of pre- and postoperative systemic immunosuppressive therapy should be considered as an important factor for the prophylaxis and prevention of anastomotic pseudoaneurysms and other graft-related complications.

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