Abstract
From using history matching to recording microseismic; exploration, completion, and production groups in the oil and gas industry don't know exactly where stimulation treatments are placed and how efficient that placement has been. Exploration geologists and geophysicists want to know placement effectiveness to relate current geologic parameters with future potential formations. Completion engineers want to use tubular and downhole hardware systems to be as cost-effective as possible and to minimize total stimulation treatment cost. Production engineers are seeking to maximize production for as long a time frame as possible. Fracturing placement and verification cuts across all segments of an asset.
With recent technology and methodology advancements, the industry can inject particulate oilsoluble tracers (OST) with the proppant and measure those tracers effectively from fracture tip to production tank. While still not accurately describing the exact fracture geometry or parameters such as fracture conductivity (fcd), the industry can now qualitatively measure production from each stage. With each stage uniquely identified by post-fracture production, fracture size and capital expenditure associated with the placement of the fracturing treatment can be optimized.
Broadview Energy recently pumped a fracturing treatment into the 637 m (2089 ft) total vertical depth (TVD) Sparky clastic zone through a 114 mm (4.5") liner string in a horizontal wellbore using mechanically operated sleeves. Broadview Energy sequentially alternated the size of the fracturing treatments along the length of the well between 7.5 t (16, 534 lb) and 5 t (11,023 lb) of 16-30 fracturing sand as the proppant. Alternating the fracture size served to isolate geologic and fluid heterogeneities.
Measuring the OST concentration from each fracture treatment showed results that were not directly proportional with the size of the treatment; namely, a 50% larger stage treatment yielded a 33% improvement in OST return. Using tracer technology to show observable variations of completion methods, Broadview Energy hypothesizes that, with further testing, it would be possible to recognize the threshold in fracture size and prevent diminishing returns in future fracture treatments with similar geologic conditions.
