Estimation of hydraulic fracture volume utilizing partitioning chemical tracer in shale gas formation

• MoM is capable to determine the swept volume of partitioning tracer under two-mobile-phase condition.
• The tracer production data is indicative of the total swept volume of fracture and fracking fluid leak-off.
• Two linear relationships of tracer tail are observed when fracture exists.
• Partitioning tracer has rapid feedback even though the injected fracking fluid is trapped in the system.

Hydraulic fracture geometry is of the interest in optimizing stimulation treatment and forecasting production potential. Current diagnostic tools such as tiltmeter and microseismic are insufficient in evaluating fracture geometry. Knowing that gas from the shale reservoir has a much higher mobility than fracking fluid, partitioning chemical tracer is employed so that tracer data can be obtained earlier and more complete. The proposed approach is examined by synthetic numerical simulations. On the semi-log plot, tracer production declined tail clearly divides into two straight-line segments. Applying the moment of methods to the entire tracer production data gives the total volume of hydraulic fracture and the invaded matrix swept by the tracer due to leak-off. Additionally, extrapolating the first segment of tracer decline tail using the exponential law yields a volume that is close to the actual hydraulic fracture volume, especially when fracture permeability is several orders larger than matrix permeability.