Rock physics based velocity-porosity correlations developed for estimation of the elastic properties of the Bakken formations of the Williston Basin, North Dakota

Rock physics models are predictive tools used to estimate the velocity, or elastic properties of formations, based on strong theoretical foundations, as opposed some simple empirical correlations that have been developed for specific regional formations. While basic rock use simplified assumptions and involve less input, more complex models, such inclusion-based velocity-porosity relation function different parameters including pore's fluid saturation type, cementation, confining pressure diagenesis. The downside is these require performing tedious calculations in cases solving differential equations. These may also differ depending type formation, example, separate be shales compared siliciclastic carbonate In this paper, we present newly can substitute modeling. correlationsare mineralogical data from Bakken formation Williston Basin, North Dakota, however, they with good accuracy other formations too. were large volumes simulation many using effective medium (DEM) theory, a commonly model. DEM composite rock, but assuming single mineral constituting rock. inclusion phase was incrementally added matrix phase. pores then modeled three (water, oil, gas) at levels finally, aspects ratios (AR) assumed simulate heterogeneity (i.e., crack, intraparticle, intergranular moldic pore geometries). constants extracted key minerals Bakken, quartz, calcite, dolomite, anhydrite, illite kerogen. Having volume fraction lab-based XRD Elemental Capture Spectroscopy (ECS) logs, linear averaging applied equivalent velocity several case studies existing lab data, which showed agreement simplicity consists simply entering input values an excel template accounts constant parameters, approach This offers great advantage their applications. workflow developing its applications one stduy Well Mountrail County will presented.