Abstract
In McMurray Formation, steam assisted gravity drainage is used as the primary in-situ recovery technique to recover oil sands. Different geological reservoir settings and long horizontal wells impose limitations and operational challenges on the implementation of steam-assisted gravity drainage (SAGD). The dual-string tubing system is the conventional completion scheme in SAGD. In complex reservoirs where dual-string completion cannot improve the operation performance, operators have adopted flow control devices (FCDs) to improve project economics. FCDs secure more injection/production points along the horizontal sections of the SAGD well pairs, hence, they maximize ultimate bitumen recovery and minimize cumulative steam-oil ratio (cSOR). This paper will focus on the optimization of outflow control devices (OCDs) in SAGD reservoirs with horizontal wellbore undulations. We present the detailed optimization workflow and show the optimization results for various scenarios with well pair trajectory undulation. Comparing the results of the optimized OCDs case with a dual-string case of the same SAGD model shows improvements in steam distribution, steam chamber growth, bitumen production, and net present value (NPV).
Highlights
The Canadian oil sands found in the prairie province of Alberta have over 165 billion barrels of oil (Alberta’s Energy Reserves and Supply/Demand Outlook Report 2017), ranking Canada as the third largest country in oil reserves in the world
Besides open-pit mining that contributes to only 10% of the total recovery, steam-assisted gravity drainage (SAGD) has been adopted and developed as an in-situ recovery technique for bitumen production [1]
This paper presents a workflow to optimize the placement and number of ports of outflow This paper presents a workflow to optimize the placement and number of ports of outflow control devices (OCDs)
Summary
The Canadian oil sands found in the prairie province of Alberta have over 165 billion barrels of oil (Alberta’s Energy Reserves and Supply/Demand Outlook Report 2017), ranking Canada as the third largest country in oil reserves in the world. The well pairs are completed with a short tubing landed at the heel section of the well, and a long tubing is extended all the way to the toe. This completion design offers two injection points in the well and leads to a better steam chamber development along the horizontal well compared to a single point production and injection. The dual tubing completion, leads to a non-uniform steam chamber growth, owing to factors such as the reservoir heterogeneity and variations in the reservoir structure [2,3,4]
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have