This paper describes the planning, drilling and completion of the first horizontal well in a Canadian vertical hydrocarbon miscible flood which is also the first medium radius horizontal well drilled by Husky.
Management set-up a multi-disciplinary task force to determine the optimum utilization of horizontal well technology and to select the first location. This task force selected Rainbow Keg River G Pool, in which a miscible flood has been in progress since 1972. A horizontal well, 16-29-108-9W6M, was subsequently planned, drilled and completed in this pool to increase oil production rate and ultimate recovery.
To minimize oil sandwich (the oil bank remaining between solvent and water) loss in this vertical miscible flood, the well was to be placed as low as possible with respect to the oil/water contact while avoiding water coning. To improve the interpretation of reservoir characteristics and fluid contacts, a program of well testing and production logging was conducted at offsetting vertical wells. To validate the interpretation and obtain additional reservoir information a vertical pilot hole was drilled through the productive reef prior to plug back and kick off for the horizontal hole.
The surface location was determined from 3D seismic, which was used to map the Keq River structural surface. A comprehensive formation evaluation program including coring, logging and drill stem testing was conducted in the vertical pilot hole, which contributed to the successful placement of the horizontal hole. The azimuth of the horizontal hole was determined from previous information about the direction of natural open fractures.
Initial production and pressure data has confirmed proper placement of the horizontal hole in the remaining oil sandwich. The productivity index of the well is more than three times that of the best vertical well in this pool.
Although the drilling and completion programs were designed to minimize complications which could lead to cost overruns, the actual well cost was 1.7 times the initial estimated cost and 2.5 times the cost of a conventional vertical well. However, cost overruns were due to lost time incidents in the vertical section, not in the horizontal section.
A study is in progress to determine optimum long term pool production strategy and acceptable horizontal well flowrate/drawdown.
Horizontal wells utilize technology which has been recognized for many years. The first U. S. patent related to a horizontal well method is dated 19281. Other U. S. patents related to horizontal wells were registered between 1932–19452–9. In 1939, L. Ranney published an article entitled "The First Horizontal Well"10.
Horizontal wells are now being considered more frequently world-wide by the oil and gas industry to improve the economics of hydrocarbon production.
Previous papers have mentioned the application of horizontal well technology in miscible floods11,12. This paper deals with a new application of horizontal well technology in a mature vertical hydrocarbon miscible flood reservoir.
The major industry resistance to utilizing horizontal well technology is due to its high cost and risk. Nevertheless, realizing the potential benefits of this technology, management set up a multi-disciplinary task force with the mandate to determine the best location for the first medium radius horizontal well.
