Application of Flow-Channel Fracturing Technique to Unlock Potential from Reservoirs with Severe Heterogeneity and Poor Lithological Characteristics
Authors: Rajagopalan V. S. , Awad M. O. , Al-Othman M. R. , Al-Ajmi M.. , Mokhtar A.. , Sheikh B.. 
Published: October 2015

Flow-Channel Fracturing Technique was considered as a possible solution for testing the reservoir characterized by poor lithological characteristic, severe heterogeneity, low permeability and fluid movement compared to the other producing reservoirs from the same field. This manuscript provides an insight to the conventional testing technique employed in this field and the methodology of the first application of Flow-Channel Fracturing technique in this reservoir in the pilot well, post job evaluation and way forward for large scale implementation for testing in other wells in the same reservoir.

The MB formation in the RA field was selected for the pilot application of this fracturing technique. This formation is described as marine shoreface sands with shale intercalations with an average thickness of about 160 ft. with average porosity varying from 5% to 27% and permeability ≤ 406 mD. This formation requires some stimulation treatment to have economical production. The historical testing technique carried out in this reservoir typically consisted of perforation with casing gun / Through Tubing Perforation gun and testing with Electrical Submersible Pump (ESP), perforation followed by standard mud acid stimulation and testing with ESP. These conventional testing techniques in this reservoir yielded only short term gains with subsequent decrease in the intake pressures of the ESP owing to poor reservoir deliverability and subsequent frequent tripping of ESP system.

The Flow-Channel Fracturing Technique was considered as a solution to improve upon the production through creation of infinite production conductivity and greater effective contact area. This technique is similar to conventional proppant fracturing techniques where fluid and proppant are used to create conductive paths in the formation layer to enhance production from new or already existing oil or gas wells. However, owing to its pulsed delivery, engineered design and innovative use of degradable fibers the Flow-Channel Fracturing Technique creates a much more conductive path, thereby increasing the rate at which hydrocarbons are produced from the reservoir.

As mentioned before, the primary goal of creating a mechanically stable propped fracture is to provide high flow capacity conduit to deliver the hydrocarbons to the wellbore with the maximum possible rate with the lowest pressure drop across the reservoir. For this purpose a production enhancement plan has been put in place for the scope of this project including three wells to be treated using the flow-channel fracturing technique. Two wells were treated on two stages while one had been treated as a single stage. The three wells were put on production post treatments, with the aid of ESP and illustrated stabilized average production without proppant flow-back issues.

The evaluation of the treatments had been performed and showed an average effective flow-channel fracture half-length of +/− 330 ft. with almost infinite conductivity. On the other hand, the total cumulative production up to date is +/− 470 STBOPD per zone. These outstanding results opens the door further application of flow-channel fracturing technique to be applied to existing offset wells and for future production enhancement strategy of KOC.