Hani H. Qutob

Applying a New Systematic and Dynamic UBD Procedures Prevented Formation Damage, Wellbore collapse and Improved Oil production

The Hassi Massoud oil field is the largest of its kind in Algeria. The reservoir was discovered in 1956 and produces from a Cambrian-age at approximately 3400 meters depth. It produces 45°API oil from a thick Cambro-Ordovician sandstone formation. This sandstone is extremely hard, abrasive and slow to drill. The reservoir is naturally fractured in some parts. Fractures are either open or plugged with materials such as shale, silica, anhydrite, pyrite and bitumen. Porosity is ranging from 6 to 12%. Generally, the permeability is low with a range of less than 1 to more than 100 md in open-fractures layers.

Identification and Characterization of Producing Fractures in Naturally Fractured Reservoirs Using PIWD

Underbalanced drilling provides an unprecedented opportunity to examine a reservoir as it is being drilled. With proper data acquisition and engineering interpretation, underbalanced drilling allows us to measure and calculate the Productivity Index while Drilling – PIWD. This data helps us locate and identify geologic anomalies such as fractures, tight zones, pinch outs, discontinuities, and water zones. A better understanding of the fracture networks and their impact on the production is critical to optimize infill drilling and produce the remaining reserves in any reservoir. Also, PIWD graph is a good indicator of reservoir productivity characterization. The real time data obtained using this graph can clearly show what kind of reservoir is being drilled and what kind of production can be expected.

Flexible 4 3/4 Inch LWD System Enhances Short Radius Horizontal Drilling Applications in Ghawar Field, Saudi Arabia

The benefit of acquiring valid formation evaluation data while drilling is becoming a very important factor in deciding the value of any reservoir characterization program. Providing this data in real time with LWD tools allows for real time data evaluation and decision-making. In addition, the ability to measure accurate LWD formation data in wells featuring a variety of high dogleg represents a significant opportunity for safe and cost-efficient well-bore construction. The development of the 4.3/4.Inch LWD system including directional, gamma ray, density, neutron and resistivity enabled Logging While Drilling and the acquisition of Triple Combo data in high dogleg (up to 68o/100ft) short radius wells without having to do multiple logging runs after landing the well. Historically the buildup sections of these wells had to be logged after the well was landed due to the inability to run LWD tools while drilling the curve section. Implementation of short radius horizontal drilling in the Ghawar field has revitalized this field and created additional recoverable reserve. Selection of this strategy above 60o/100ft is based on cost, drilling time and minimizes drilling through tough formations such as the anhydrite above the Arab-D reservoir, as this technique provides a shorter curve section. This paper describes the results of these case studies. The knowledge, experience and lessons learned that lead to overcoming the limitations faced in the drilling of ultra-short radius wells will also be addressed and discussed.