CHARACTERIZATION AND IMPLICATIONS OF CARBONATE MASS TRANSPORT DEPOSITS WITHIN THE UPPER LEONARDIAN FIRST BONE SPRING CARBONATE INTERVAL: DELAWARE BASIN, SOUTHEAST NEW MEXICO

Compositional characteristics of MTDs in the First Bone Spring Carbonate (FBSC) interval of the Delaware Basin are variable; specifically, in a deep basinal setting where these deposits can not only decrease reservoir quality, but also present geologic hazards to unconventional exploration. Bone Spring detrital carbonates have been studied previously for their potential as hydrocarbon reservoirs near basin margins. Yet, little or no research has been conducted to study these deposits: in the FBSC, in a deep basinal setting, compositionally, or as geologic hazards. Further, an effort to predict their distribution has not been undertaken. Complex stratigraphy in the FBSC makes it difficult to predict the occurrence and distribution of MTDs in detail. In addition, encountering these deposits in the lateral has the potential to significantly increase operating costs. Thus, understanding MTD compositional variation and distribution throughout the FBSC is crucial to locating hazardous areas across the region, and enables the identification of areas for development or avoidance that may have been overlooked.

Encompassing ~4,350 km², the study area is located in the northeastern portion of the Delaware Basin, and includes part of eastern Eddy county and the southern half of Lea county in southeast New Mexico. Analysis of core, thin-sections, and XRD data allowed for the identification and classification of variable compositions of MTDs in the FBSC. Identified MTD compositions were correlated with log responses to establish typical log signatures, enabling the identification these deposits with limited data sets. Further, establishing characteristic log signatures for these deposits facilitated the creation of a model for predicting the distribution of MTDs and their variable compositions based on relative net/gross values established across the study area. Initial results indicate this modeling technique to be an effective method for interpretation of vertical and spatial changes in lithology, and enables the visualization of MTD compositional variation across the study area and throughout the FBSC. Some MTD compositions appear to be more geologically hazardous. While these have a greater propensity to occur where MTDs are more prevalent, a trend for the distribution of such deposits hasn’t yet emerged.