Effect of Shear Stress Buildup at the Interface of Sand Control Screen and Oil Sand on the Screen Performance in SAGD

SAGD 防砂筛管与油砂界面剪切应力的积累对筛管性能的影响

• 批准号: RGPIN-2017-06257
• 负责人: Nouri, Alireza
• 金额: $ 1.75万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=712140
• 关键词: Effect; Shear; Stress; Buildup; Interface

Steam Assisted Gravity Drainage (SAGD) is the main thermal technique for in situ heavy oil recovery in Canada. This technique employs two horizontal wells that are supported against collapse by the installation of screen liners called Sand Control Devices (SCDs). SCDs are designed to (1) control sand production while allowing the flow of reservoir fluids into the well; and (2) allow the discharge of fine materials to avoid plugging of the screen and pore spaces behind the screen. SAGD projects have high operating and capital expenditures. Issues related to SCD performance, such as excessive plugging, cost the Canadian oil industry a significant amount of time and money. Due to the lack of certainty in SCD performance prediction, the industry often opts for conservative, more expensive design decisions. With recent volatility in oil prices, avoiding unnecessary costs is critical for Canada to remain competitive in today's oil market. A better understanding of SCD performance would help to optimize the design of less expensive completions, such as slotted liners, to improve their performance, avoid expensive alternatives and reduce wellbore intervention costs. The proposed research is concerned with the fundamental investigation of the impact of shear stress buildup at the SCD-formation interface on sand production and plugging. The stress builds mainly due to reservoir thermal expansion, which is restricted by the SCD. The hypothesis is that the shear stress exacerbates sanding by destabilizing sand bridges behind the slots. Currently, design criteria are excessively conservative, resulting in either the use of expensive SCDs such as wire-wrapped screen, or the use of narrower slots in slotted liners, hence, increasing plugging potentials and lowering wellbore productivity. An SCD design which allows wider slots combined with the installation of slip joints to relieve the interface shear stress is hypothesized to result in similar amounts of sanding compared to the use of narrower slots without slip joints. The use of wider slots reduces slot plugging and allows a lower number of slots to be cut in the liner, hence, less SCD manufacturing costs and improved liner integrity. An improved SCD design is expected to lead to the development of procedures and technologies that result in higher wellbore productivity, lower well completion and workover costs, and lower environmental impact due to smaller amounts of produced contaminated sand. The outcome is lower capital and operating expenditures for the heavy oil production industry which will enable Canadian industries to compete despite low oil prices. Another benefit to Canada is the training of HQP that will advance testing methods, create scientific and practical knowledge in a critical area, and disseminate through journal and conference publications. These will help Canada to assert its position at the forefront of R&D in science and engineering.

蒸汽辅助重力泄油（SAGD）是加拿大稠油原位开采的主要热采技术。该技术采用两口水平井，通过安装称为防砂装置（scd）的筛管来防止坍塌。scd的设计目的是：(1)控制出砂，同时允许储层流体流入井中；(2)允许细粒物料排出，避免堵塞筛网和筛网后面的孔隙空间。