Geological Characterisation of Depleted Oil and Gas Reservoirs for Carbon Sequestration Potentials in a Field in the Niger Delta, Nigeria

The injectivity, containment and storage capacity of sandstone reservoirs in a field in the Coastal Swamp depobelt of the onshore eastern Niger Delta were evaluated using wireline logs and seismic data to assess their potentials for carbon dioxide storage and geosequestration. The reservoir formation consists of multilayered alternating beds of sandstone and shale cap rocks. Active seismicity and fracturing intensity are low and growth faults provide the reservoir sealing mechanisms. Three reservoirs were delineated at depths between 3319 m and 3539 m which will keep injected CO2 in a supercritical state. The reservoir depth of at least 800 m, porosity and permeability of more than 10 percent and 20 mD, and a caprock thickness of at least 10 m, in addition to geothermal gradients of 13.46 to 33.66 ºC /km are the ideal conditions for the efficacy of storage. Comparison of the derived reservoir and seal properties such as porosity, permeability, thickness and depth with the minimum recommended site selection criteria shows that the reservoirs are potential candidates for carbon geosequestration with a total theoretical storage capacity of 147MM tons.

Evaluation of Onlay Island Flap Technique in Shallow Urethral Plate Hypospadiasis

Background: Hypospadias is one of the most common congenital genital anomalies in males that necessitates to be operated early in infancy (when 6 to 9 months old). On the other hand, hypospadias is a challenging field of pediatric urology with multiple reconstruction techniques. A perfect hypospadias repair is supposed to return urethral continuity with sufficient caliber, eradicate phallus curvature, and supply an acceptable appearance with low complications. Objectives: This study aimed to evaluate the outcomes of using onlay island flap technique in the repair of hypospadias with shallow urethral plate. Patients and Methods: In this prospective study within June 2012 to December 2013, we performed onlay island flap procedure to repair hypospadias with shallow urethral plate measuring less than 6 millimeter. This technique was selected for all types of hypospadiasis except subcoronal type. Nesbit’s dorsal plication procedure was established for chordee. In cases with very small glans, urethroplasty was performed without glansplasty. Results: Twenty three patients with mean age of 30 (range 10 - 60) months underwent onlay island flap repair; all had a shallow urethral plate < 6 mm, 3 had a very small glans, and 18 had chordee. Meatus was located in distal shaft in 5 cases, mid shaft in 8, proximal in 6 and penoscrotal type in 4 patients. Chordee was corrected with Nesbit’s dorsal plication in 16 cases. Complications were: meatal stenosis in 2 cases and urethrocutaneous fistula in 2 patients, all of which were repaired surgically. Mean follow up time was 13 (3 - 20) months. All cases that had glansplasty have excellent esthetic appearance. Conclusions: This technique offers acceptable results regarding meatal stenosis, urethrocutaneous fistula and esthetic outcome.