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: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=679677
• 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技术。该技术采用两个水平井，通过安装称为防砂装置 (SCD) 的筛管来防止塌陷。 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) 允许排出细料，以避免堵塞筛网和筛网后面的孔隙空间。***SAGD 项目的运营和资本支出较高。与 SCD 性能相关的问题（例如过度堵塞）给加拿大石油工业带来了大量的时间和金钱。由于 SCD 性能预测缺乏确定性，业界经常选择保守且成本更高的设计决策。鉴于近期油价波动，避免不必要的成本对于加拿大在当今石油市场保持竞争力至关重要。更好地了解 SCD 性能将有助于优化较便宜的完井设计，例如割缝衬管，以提高其性能，避免昂贵的替代品并降低井眼干预成本。***拟议的研究涉及 SCD-地层界面处剪切应力累积对出砂和堵塞的影响的基础研究。应力的产生主要是由于储层热膨胀而产生的，而热膨胀受到 SCD 的限制。假设剪切应力破坏了槽后面的沙桥，从而加剧了砂磨。目前，设计标准过于保守，导致要么使用昂贵的SCD，例如绕线筛管，要么在割缝衬管中使用较窄的槽，从而增加了堵塞潜力并降低了井眼生产率。假设 SCD 设计允许更宽的槽，并安装滑动接头以减轻界面剪切应力，与使用不带滑动接头的较窄槽相比，可以产生类似的打磨量。使用更宽的槽可减少槽堵塞，并允许在衬套中切割较少数量的槽，因此，可降低 SCD 制造成本并提高衬套完整性。 ***改进的 SCD 设计预计将导致程序和技术的开发，从而提高井眼生产率、降低完井和修井成本，并由于产生的污染砂量减少而降低对环境的影响。其结果是重油生产行业的资本和运营支出降低，这将使加拿大工业在低油价的情况下仍具有竞争力。加拿大的另一个好处是总部的培训，将改进测试方法，在关键领域创造科学和实践知识，并通过期刊和会议出版物进行传播。这些将有助于加拿大确立其在科学和工程研发前沿的地位。