Towards Commercialization of the UTF Project Using Surface Drilled Horizontal SAGD Wells

Abstract

Abstract The Underground Test Facility (UTF) Demonstration Project was started in 1984 and the first two phases have been completed. The UTF Project current Phase B-2 is proceeding with the testing of the tunnel drilled Steam Assisted Gravity Drainage (SAGD) wells. The UTF Project is producing about 320 cubic metres per day (m3/d) [2,000 barrels per day (BPD)] of dry bitumen which is trucked to market. The higher than predicted bitumen sales revenue has been reinvested into the project and these extra funds are being used to drill and operate SAGD wells from the surface. This paper provides some important concepts for using SAGD well pairs drilled from the surface to produced bitumen on a commercially viable basis in the Athabasca Oil Sands. The expansion demonstration program consists of drilling and completing from the surface, two 750 m SAGD horizontal well pairs, to produce an additional 320 m3/d. This will increase bitumen production from the UTF Project to 640 m3/d (4,000 BPD). Key features covered are surface drilling and completion of long horizontal wells, steam injection and monitoring, well production control, surface facilities for producing dry bitumen and getting the product to market. The design and operating aspects of a 4,800 m3/d (30,000 BPD) commercial project are reviewed. Project costs and economics favour surface drilled horizontal wells over wells drilled from underground tunnels. The purpose of this new SAGD technology is to economically develop the 140 billion cubic metres (900 billion barrels) of oil-in-place in the Athabasca oil sands region of Alberta. Of these, more than 50 billion cubic metres (330 billion barrels) are now recoverable using the SAGD technology. The nine industry participants in the UTF project own about 50% of oil sands leases in Athabasca, hence the high level of interest in developing new technologies to extract the bitumen. There are other major factors which need to be provided in order to commercially develop this resource. The paper also outlines the requirements for oil sands development in Athabasca and discusses nurturing the expansion of existing USA heavy oil markets, building a heavy crude oil pipeline from Athabasca region to Edmonton and taking advantage of new technologies such as SAGD to significantly reduce capital and operating costs. The Underground Test Facility (UTF) The purpose of the UTF is to test the concept of in situ bitumen extraction using the Steam Assisted Gravity Drainage (SAGD) process. The key features of the current UTF Project are shown in Figure 1. It consists of two vertical shafts 3.3 m in diameter penetrating 140 m of overburden, 20 m of oil sands and 15 m of limestone below which are located horizontal tunnels 5 m wide and 4 m high. The tunnels are in solid limestone and are larger where the wells are located (8 m wide × 5 m high) and smaller (4 m wide × 3 m high) where the tunnels serve only to complete the access and ventilation circuit.