Tight reservoir leads to challenging conditions and low production

An operator in western Egypt wanted to increase production from older wells that yielded 9,000 bbl in 3 years. Most wells in this field produced for just a few months after perforation and, in some cases, ceased flow right after perforation.

The targeted formation is characterized as fine- to very fine-grained sandstone interbedded with shale layers. This tight reservoir consisted of high closure gradients, which made hydraulic fracturing challenging. Typically, this formation's properties are:

• 250 to 280 degF [121 to 138 degC] bottomhole static temperature
• 3.5 to 6.0 million psi Young’s modulus
• 10 to 12% porosity
• 0.1 to 1 mD

The customer previously conducted hydraulic fracture treatment on workover rigs using a frac packer and tubing that was limited to a maximum working pressure of 10,000 psi. Conventional fracture designs were prepared using 40 to 45 × 10-3 borate fluids and 20/40 high-strength proppant. Effective fracture half-length and conductivity of the fracture proppant pack drove production from the reservoir.

The fractures were conservatively designed in terms of rate and proppant concentration to manage both risk and treatment placement. However, this conservative approach impaired proppant-pack conductivity and the effectiveness of the fracture half-length. In some cases, premature screenouts occurred, resulting in lost production and well abandonment. Due to the poor results using these conventional hydraulic fracturing techniques during initial exploration and development, the wells were deemed uneconomical.

Flow-channel fracturing technique used as last chance to save wells

The customer chose to use the HiWAY technique to address these challenges and bring the well back to economic levels of production. The HiWAY technique significantly increases fracture conductivity while reducing water and proppant production. As the first fracturing technique of its kind, the HiWAY technique creates an open pathway inside the fracture, enabling hydrocarbons to flow through stable channels rather than the proppant—optimizing connectivity between the reservoir and the wellbore.

Outstanding results opens door to other wells in region

After Schlumberger used the HiWAY technique, the well initially produced more than 500 bbl/d—record for this well. The customer recovered 8,000 bbl in just 3 months, compared with 9,000 bbl in 3 years. The outstanding results impressed the operator, which now plans to use the stimulation technique on other older wells in the region.