Optimum well spacing is one of the main development questions in Appalachian Marcellus shale assets. Answering this question requires a good understanding of well-to-well interactions, which is dominated by hydraulic fracture geometry and structural geology (faults, natural fractures, layering, etc.) A comprehensive data gathering exercise and a reservoir characterization study has been in progress since the start of 2012 at a pilot pad. The pilot includes three horizontal producers and a horizontal observation well. Downhole pressure and temperature, DTS, chemical tracer, microseismic, and PLT data were collected during hydraulic fracturing and production of the wells. Later these data were integrated with the existing 3D-seismic, core and log data to construct a subsurface model.
This paper summarizes two aspects of the subsurface characterization work:
Integration of data from different sources: Results from each data source are summarized in the first half of the paper. Also, consistency of the results is discussed. Later, well-to-well connectivity and stimulated reservoir volume (SRV) based on pilot data are shown.
Dynamic modeling of the pilot: In the second half of the paper, history matching process is presented. It focuses on the integration of static models and observations from pilot data. Practical aspects of the modeling work, such as gridding, representation of SRV, hydraulic fractures, and geological features (natural fractures, faults/lineaments) and model initialization are discussed. At the end, results of the history match study are presented.
In Northcentral Pennsylvania, Shell's lease position is mainly situated along the crests and flanks of the three ENE-WSW anticlinal folds. Generally, net pay thickness across Shells acreage ranges from 90 ft. in the northwest to about 200 ft. in the southeast and the estimate of gas-in-place, also, follows this trend. The average depth of the reservoir ranges from about 3000 ft. TVDss to 6000 ft. TVDss.