Cross-Disciplinary Integration Optimizes Wellbore Geosteering In Parsley's Trees Ranch Project By Jennifer Hernandez, J. Alexandra "Ali" Sloan and John Terwilliger HOUSTON-In addition to its leading Midland Basin acreage position, Parsley Energy Inc. has established a contiguous acreage position in the southern Delaware Basin in West Texas, which is prospective for multiple stacked stratigraphic layers and landing zones, including the Wolfcamp and Bone Spring formations. Initial horizontal drilling in the Delaware Wolfcamp play was focused in the Phantom Field trend, which is situated in the eastern portion of the basin where the Wolfcamp is deeper and thicker. More recently, development has pushed farther south into the more structurally complex portion of the basin. Deep-seated structural features influence the thickness and complexity of the Wolfcamp section throughout this region. Parsley Energy's Trees Ranch project in Pecos County is located in a unique portion of the southern Delaware Basin. It is bounded to the west by the Waha structure (a series of thrust faults and folds), to the east by the Central Basin Platform, and to the southwest by the Coyanosa anticline structure. The Wolfcamp formation on these bounding structures is thin to nonexistent. Within Trees Ranch, the Wolfcamp's thickness is similar to the prolific Phantom Field trend that extends into Ward and Loving Counties. 62 THE AMERICAN OIL & GAS REPORTER