Abstract

The Underground Test Facility Demonstration Project is currently producing 2000barrels/day of dry bitumen which is trucked to market. Over one million barrelsof bitumen has been produced and sold from Phase B as of February 1995 (sincestart-up bout two years ago).

This paper provides some important concepts for using horizontal Steam Assisted Gravity Drainage (SAGD) well pairs drilled from the surface to produce bitumenon a commercially viable basis in the Athabasca Oil Sands.

The expansion demonstration program consists of drilling and completing fromthe surface, two 750 metre SAGD horizontal well pairs, to produce an additional2000 arrels/day (BPD). This will increase bitumen production from the UTFProject to 4000 BPD.

Key features covered are surface drilling and completion of long horizontalwells, steam injection and monitoring, well production control, surfacefacilities for producing dry bitumen and getting the product to market. Thedesign and operating aspects of a 30,000 BPD commercial project are reviewed.Project costs and economics favor surface drilled horizontal wells over wellsdrilled from underground tunnels.

There are over 900 billion barrels of bitumen oil-in-place in the Athabasca oilsands of Alberta. Of these, more than 350 billion barrels are recoverable usingthe SAGD technology.

The nine industry participants in the UTF project own about 50% of oil sandsleases in Athabasca, hence the high level of interest in developing newtechnologies to extract the bitumen.

The paper also outlines the requirements for oil sands development in Athabascaand di8cusses nurturing the expansion of existing U.S.A. heavy oil markets, building a heavy crude oil pipeline from Athabasca region to Edmonton andtaking advantage of new technologies such as SAGD to significantly reducecapital and operating costs.

The Underground Test Facility (Utf)

The purpose of the UTF is to test the concept of the in-situ bitumen extractionprocess called the Steam Assisted Gravity Drainage (SAGD) process.

The key features of the current UTF facility are shown in Figure 1. It consistsof two vertical shafts 3.3 metres (m) in diameter penetrating 140m ofoverburden, 20 m of oil sands and 15 m of limestone below which are locatedhorizontal tunnels 5 m wide and 4 m high. The tunnels are in solid limestoneand are larger where the wells are located (8m wide × 5 m high) and smaller (4m wide × 3 m high) where the tunnels serve only to complete the access andventilation circuit. From the tunnel walls, horizontal wells are drilledupwards through the limestone and then horizontally into the oil sands payzone.

The current Phase B program consists of three well pairs spaced 70 metres aparthorizontally. Each well pair consists of an injection well (upper) andproduction well (lower) spaced 3 - 5 metres vertically apart near the bottom ofthe pay. The six wells are each 600 metres long and are drilled horizontally,500 metres in the oil sands pay zone.

Utf Sagd Project Location
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