Geo-mechanics of Batch Injection in Horizontal Disposal Wells – North Sea

Zaki, K.; Kristiansen, T. G.; Abou-Sayed, A. S.; Summers, C. W.; Wang, G. G.; and Sarfare, M.D.
Alaska Rocks 2005, The 40th U.S. Symposium on Rock Mechanics (USRMS), Anchorage, Alaska, June 2005.


The disposal domain concept is arguably accepted as the prevalent storage mechanism during the batch injection of drill cuttings. The disposal domain is best thought of as an elliptical realm surrounding the well. This phenomenon is well documented by field and laboratory observations and has been addressed in previous work. Most studies and field operations have centered around vertical or near vertical wells. Rarely have horizontal wells been designed for conversion to injectors or used for disposal and therefore, the effect of batch injection and the created disposal domain have not been addressed. The current paper will provide an integrated look at the fracturing process that occurred in a horizontal disposal well. The well is located in the Valhall Field, North Sea, offshore Norway. The well has multiple perforated intervals. The work will address a modified disposal domain concept as it applies to horizontal wells. The paper illustrates a history of the fracture nature (geometry and extent) and propagation across the various layers. Comparison of the field pressure history and the simulation results will be addressed. Further studies to address the effect of a workover carried out in the well, plug placement, are currently under way. These modifications will be addressed in a future paper.