3D Fracture Modeling and Fracture-Height Mapping Using Different Logging Methods in the Vertical Well

Abstract

Modeling the correct fracture geometry in hydraulic fracturing simulators is challenging. Mapping the fracture can reduce the degree of uncertainty and help adjust the hydraulic fracturing model in the simulator. To map fracture height, acoustic or temperature logging can be used, as well as pulsed-neutron logging combined with tagged nonradioactive tracer (NRT) neutron-absorbing proppant. This article compares the data for modeling a hydraulic fracture in pseudo three-dimensional (P3D) and full 3D (F3D) hydraulic fracturing simulators with the results of studies of mapping fracture height in a well. Analysis of well survey data allowed assessment of the degree of fracture penetration from an oil reservoir through a clay barrier in an aquifer. Interpretation of cross-dipole acoustic logging, which characterizes impaired continuity of the medium, coincides with the interpretation of dual-burst thermal-decay time log (DBTDT) data, reflecting NRT proppant placement in hydraulic fractures near the wellbore. Bottomhole pressure analysis and comparison of production before and after hydraulic fracturing also confirm fracture height measured using two methods: F3D and P3D modeling. The experiment showed that F3D modeling more accurately calculates fracture height than P3D modeling. The interpretation of temperature logging does not correspond to the fracture model and is not supported by other logging methods; therefore, this type of logging cannot be used to adjust fracturing design models.