Integrating horizontal borehole imagery and cluster analysis with microseismic data for Niobrara/Codell reservoir characterization, Wattenberg Field, Colorado, USA

Unconventional reservoirs are multi-variate problems requiring integration of data across multiple disciplines. Integration of multi-scale data to solve shale plays has become increasingly more common (Roth (2010), Norton (2011), Quirein et al. (2012), Xie et al. (2012), Close et al. (2012). In this thesis I examine microseismic data heterogeneity by integrating borehole imagery and cluster analysis of the well logs along the horizontal sections of two horizontal wells to delineate microseismic data trends. Microseismic data are the direct measurement of the real time hydraulic fracture treatment or stimulation and reveals the reaction of the subsurface to stimulation. Microseismic data are often not studied at the wellbore scale, yet this is exactly where the stimulation initiates.;Horizontal wells are rarely horizontal. The well can traverse tens of feet from the heel to the toe of the well and undulate in and out of the pay. In addition, the geologic structure intersecting the well, such as faults, can cause the well to penetrate varying lithology without a change in well deviation or azimuth. Thus, stage locations along the horizontal section of the well are in and out of the pay and as a result affect the stimulation and the microseismic data. Therefore, I examine the lithological and structural components along the entire horizontal section of two wells and utilize the results to delineate the microseismic data heterogeneity.;Integrating horizontal borehole imagery and cluster analysis can aid in quantifying the lithology and structure controlling microseismic data heterogeneity. Areas depicting a distinct difference in microseismic data trends are primarily due to the lithology and structure along the horizontal wellbore. It was found that linear microseismic data trends are due to lack of a natural fracture network and are affected by the modern day stress field and clustered microseismic data trends are due to a complex natural fracture network and an greater amount of natural fractures. Additionally, the microseismic magnitude was found to be directly related to the lithology and structure along the horizontal wellbore.;Microseismic data heterogeneity is dependent on the lithology and structure along the horizontal section of horizontal wells. The results of this integrated, multi-scale study are used to explain production in two horizontal wells, aid in the interpretation of future microseismic data sets, and improve future well locations and completions in Wattenberg Field.