Journal of Canadian Petroleum Technology
Volume 48, Number 11, November 2009, 11-15

Abstract

The steam assisted gravity drainage (SAGD) pilot test in the LiaoHe oilfield of China is the first SAGD project conducted in China in the deeper bitumen reservoir (650 – 800 m), using a combination of vertical injectors and horizontal producers. Temperature observation wells play an important role in the understanding of the pilot performance and optimization of the operation process. This paper will present the objectives, principles, interpretation and application of the temperature observation wells in the pilot area. A number of production problems were identified and solutions were sought to improve the SAGD performance through the use of temperature and other data obtained from the observation wells.

Introduction  

This paper is a continuation of CIPC paper 2006-146. That paper introduced the successful test of the SAGD pilot in a deep biutmen reservoir in China(1). The pilot has been expanded to include 12 horizontal wells since the presentation of the original paper. The earlier two wells have reached a daily oil rate of over 100 m3/day per well. The current recovery factor is approximately 27% and the anticipated ultimate recovery is over 60%.

Compared with most current Canadian SAGD projects, the reservoirs in the LiaoHe oil field operated by PetroChina presented two challenges to the use of SAGD technologies. First, the reservoir depth exceeded 500 m (530 – 810 m) compared to the typical 200 – 500 m present in most Canadian SAGD projects(2), which increased the heat loss from the injection wellbores to the overburden Second, the reservoir had been subjected to primary production by Cyclic Steam Stimulation (CSS) prior to the implementation of the SAGD process while for the majority of the Canadian SAGD projects the technique is applied directly to a virgin reservoir. The current recovery factor by CSS in the LiaoHe reservoir is approximately 20% of the OOIP. This prior depletion by CSS complicated the conversion to SAGD applications and determination of operating parameters caused by the alteration in the distribution of the remaining oil saturation present in the formation (Figure 1).

© 2009. Society of Petroleum Engineers

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History

• Original manuscript received: 15 May 2008
• Meeting paper published: 17 June 2008
• Revised manuscript received: 18 September 2009
• Manuscript approved: 22 September 2009