The Role of Autonomous Flow Control in SAGD Well Design

Abstract

Steam-assisted gravity drainage (SAGD) has become the de-facto standard for commercial development of heavy oil and bitumen (HO-B) reserves in a significant number of fields. Although SAGD has proved to be a highly effective technique, many uncertainties and unanswered questions still exist, leaving room to improve production and optimize the economics of a SAGD installation. One notable improvement originating from recent field experience is the novel usage of injection/inflow control devices (ICDs) in a conventional SAGD well pair. The use of a properly designed ICD completion is proving beneficial to both steam chamber development as well as improving the inflow profile of the producing well of the SAGD pair. Work conducted in the Surmont field of Alberta, Canada provided an excellent starting point to optimize flow control improvements to the SAGD process. However, significantly more needs to be added to the discussion to establish best practices for ICD selection and usage and to quantify the benefits gained from using autonomous ICDs in HO-B reservoirs. It is the goal of this paper to provide a useful reference for ICD behavior and theory, selection criteria, the unique role of ICDs in managing steam chamber development, steam fingering control, and management of the subcool temperature (steam trap control). Representative field simulations of Albertan bitumen sand are used as the basis for describing overall trends in the use of flow control in the SAGD process.

Design of flow control devices in steam-assisted gravity drainage (SAGD) completion

“…6 Expanded view of RCP insert in base pipe Movement of the RCP internal disk under oil and gas flow conditions (Halvorsen et al 2016) J Petrol Explor Prod Technol Fig. 7 View of a Hybrid ICD assembly with transparent housing subassembly (Banerjee et al 2013b) One of multiple pathways set in the circumference of a hybrid FCD subassembly (Banerjee and Hascakir 2015) Garcia et al 2009;Loretz and Hosatte 2007;Russell et al 2013a, b). Yet all FCDs may be sorted into three broad categories: channel-style FCDs, restriction-style FCDs, and autonomous FCDs (Al-Khelaiwi and Davies 2007;Banerjee et al 2013a;.…”

“…By distributing the pressure drop over multiple subcomponents, no one individual point of pressure loss is critical to overall function. Cross-sectional flow area through this geometry is 4-10 9 larger than other autonomous FCDs, significantly lowering internal velocities and thus, lowering the risk of both plugging and erosion (Banerjee et al 2013b). The staggered restrictions within this geometry also serve to add a secondary control over steam flashing.…”

“…Too low an average subcool and steam breakthrough will occur at points along the producing lateral, negatively impacting cumulative steam to oil ratio (cSOR), thermal efficiency, and the economics of the project. Too large an average subcool and liquid occupies a significant fraction of the steam chamber, preventing the free movement of steam to the chamber boundaries and potentially flooding the injector well itself (Banerjee et al 2013b;Carpenter 2015;Gotawala and Gates 2012). Flow control devices (FCDs) are used to overcome the problems with uneven steam trap height, allowing for more aggressive production rates and less manipulation of subcool.…”

“…Channel-style flow control devices (FCDs) are one of the earliest geometries of FCDs used downhole in the oil and gas industry (Banerjee et al 2013b;Li et al 2013). It is the first type of FCD used to equalize production on a horizontal producer (Al-Khelaiwi and Davies 2007; Henriksen et al 2006;Mikkelsen et al 2005) as well as the first geometry used in a SAGD production well (Stalder 2013).…”

Flow Control Devices in SAGD Completion Design: Enhanced Heavy Oil/Bitumen Recovery Through Improved Thermal Efficiencies

“…Too low an average subcool and steam breakthrough will occur at points along the producing lateral, negatively impacting cSOR, thermal efficiency, and the economics of the project. Too large an average subcool and liquid occupies a significant fraction of the steam chamber, preventing the free movement of steam to the chamber boundaries and potentially flooding the injector well itself (Banerjee et al 2013b;Carpenter 2015;Gotawala and Gates 2012).…”