Lloydminster, Saskatchewan Vertical Well SAGD Field Test Results

Abstract

Summary Husky Energy's Pikes Peak steam project has been highly successful using CSS and follow-up steam drive for vertical and directional wells located on the bottomwater-free structural high inside the oil/water contact of the Waseca channel sand reservoir(1). In some areas, recoveries of up to 90% have been achieved with a cumulative steam/oil ratio (SOR) of less than 3.0. Use of CSS with follow-up drive has not been successful where bottomwater is present outside the oil/water contact. Some improvement in performance was achieved using large CSS slugs and high-steam injection rates, but in some locations CSS performances were still poor and conversion from CSS to drive has not been successful in any location. In 2008 Husky initiated a field test of a single vertical well SAGD configuration in an area outside the oil/water contact to evaluate an alternate process in which the "conventional" CSS performance of 10 wells was poor from the second or third stimulation onward. The results from the first single vertical SAGD well pilot demonstrated that a single vertical well SAGD configuration could be successfully completed and operated. The field data are being evaluated using empirical and numerical modelling methods to develop completion and operating strategies that optimize future produced oil rates and SORs. Another benefit of the field test was its demonstration of a low-cost and rapid method to help determine if a reservoir has sufficient vertical permeability for horizontal well SAGD to work.

Experimental and Numerical Investigation on Infilled Vertical Well LASER-Assisted SAGD

“…As the first cycle is mainly the well vicinity preheating, the fluid injected is limited, and the heated radius is just within 10 m. In the second cycle, it is shown that the heated region likes a circle, with no effect of current SAGD steam chamber and producer, due to the far distance of the current heat sources. While during the third cycle, the injected steam tends to connect the current steam-heated region of the SAGD wellpair, and the heat region does not like a circle, with longer heated section perpendicular to the horizontal well and shorter section parallel -218.17 14 Geofluids to the horizontal well. In the fourth cycle, the temperature profile shows that the injected fluid has contacted with the SAGD steam chamber, meaning that it is timing to convert the vertical wells to continuous injection mode.…”

“…In order to produce the bypassed deposits of existing SAGD wellpair, infilled wells are suggested to deploy in the interwellpair region [9][10][11][12]. Owing to the advantages of flexible operation regulation and better suitability in interbedded reservoirs, multiple vertical wells are the first choice of infilled drilling [13], which has been successfully implemented in several SAGD projects in Canada and China [14]. Infilled horizontal well or wedge well is also an alternative [15], while it is more suitable for wellpairs with less geologic heterogeneity as the shale barriers are likely to reduce the drill encounter rate of infilled horizontal wells.…”

Oil Recovery From Thin Heavy-Oil Reservoirs: The Case of the Combined-Thermal-Drive Pilot in the Morgan Field

“…The highly successful Pikes Peak project (Miller and Xiao 2010) is a good example of the application of steam-injection technology to the thicker Lloydminster reservoirs. The challenge has been to translate that success to thinner formations (e.g., those encountered in the Morgan field).…”

On the optimum operating temperature for steam floods

“…6). While fine scale models are required for full-field simulation studies, relatively coarse layer-cake models are often suitable for preliminary screening of steam flooding projects, assessment of uncertainties as well as history-matching experimental and actual steam-injection projects [31,32]. Each simulation cell is of dimension 40 m x 12.5 m x 1 m.…”