Elemental Data Collected in the Berea Sandstone of Eastern Kentucky: Applications to Wellbore Placement, Horizontal Chemosteering and Completion Strategy

Abstract

The use of elemental data derived from energy-dispersive X-ray fluorescence collected from drill cuttings is starting to gain popularity in the oil and gas industry, with applications spanning from spud through completion of the well. Whether analyzing the data prior to, during, or after drilling a horizontal well, there are many practical applications of utilizing this data. In this study, elemental data was used to build a chemostratigraphy within the Berea Sandstone and bounding units in three wells drilled in eastern Kentucky. Samples were collected on one Berea core at one foot intervals, on cuttings collected from three Berea vertical pilot holes at five foot intervals and along the corresponding horizontal wellbores at ten foot intervals. This data was utilized to help select the target zone, determine the stratigraphic position of the wellbore and to make completion recommendations. Subsequently, this dataset also proved the validity of elemental data collection as a useful component to geosteering. The elemental data collected from the pilot hole cuttings is compared to the elemental data collected from the horizontal cuttings in order to determine from which chemostratigraphic section the horizontal cuttings originated. Once the relationship between horizontal elemental data and pilot hole chemostratigraphic zonation is determined, a “look back chemosteer” of the wellbore path is developed. This study shows the usefulness of using elemental data in conjunction with gamma ray data to verify the stratigraphic position of the wellbore path. Further, results suggest that access to real-time elemental data can be a major benefit when drilling in areas where weak gamma ray character and limited structural control can make geosteering a horizontal wellbore difficult. Understanding chemostratigraphic packages within the Berea Sandstone can help guide target selection and wellbore placement prior to kicking off a horizontal wellbore as well as the ability to “chemosteer” the well real time. Finally, having accurate knowledge of where the wellbore was drilled based on interpretation of elemental data and determination of chemostratigraphic packages can help guide the completion of Berea wells, allowing engineers to avoid completing less desirable reservoir facies.

AAPG Datapages/Search and Discovery Article #90258 © 2016 AAPG Eastern Section Meeting, Lexington, Kentucky, September 25-27, 2016