气藏型储气库出砂规律研究的新方法

A New Method for the Study of Sand Production in Gas Reservoir Storage

廖伟 罗双涵 胡书勇 张赟新 罗海涛

LIAOWei LUOShuanghan HUShuyong ZHANGYunxin LUOHaitao

中国石油新疆油田储气库有限公司, 新疆 呼图壁 831200 油气藏地质及开发工程全国重点实验室·西南石油大学, 四川 成都 610500

Gas Storage Co. Ltd., PetroChina Xinjiang Oilfield, Hutubi, Xinjiang 831200, China National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China

新疆H储气库受储气库强注强采运行模式影响，调峰采气过程中储层易发生出砂风险，从而严重影响储气库的寿命和调峰能力，亟需开展储气库出砂规律研究，确保储气库调峰保供能力。针对常规岩芯驱替出砂实验条件下岩芯出砂量很小，实验过程中很难监测到出砂量等问题，提出了一种新的实验方法，即在常规驱替出砂实验的基础上，通过核磁共振仪测量岩芯实验前后孔径分布与孔喉分布变化。该方法解决了常规出砂实验过程中出砂量过小难以监测的难题，从微观角度更加全面地探究了地层出砂规律。利用此方法，分析了流速、生产压差、渗透率、含水率和地层压降等5种因素对地层出砂的影响，实验研究结果表明： 1)流速越大，岩芯渗透率与出砂量均先增大再减小最后保持不变； 2) H储气库的临界流速为4.14 L/min，临界生产压差为5 MPa； 3)孔径分布分析表明，含水率与地层压降是影响新疆H储气库地层出砂的主要因素； 4) H储气库在早期无水生产时，适当出砂反而会提高地层渗透率进而提高气井注采气能力。

Xinjiang H gas storage is affected by the strong injection and production operation mode of gas storage, and the risk of sand production is prone to occur in the reservoir during peak shaving and gas production. Once sand is produced, it will seriously affect the life and peak shaving capacity of the gas storage, and there is an urgent need for studies on sand production in the gas storage. It is difficult for regular research to ensure the capacity of gas storage for peak shaving and supply, and monitor sand production during the conventional experiment. In view of this, this paper proposes a new experimental method, that is, on the basis of the conventional sand displacement experiment, the pore size distribution and pore throat distribution before and after the core experiment are measured by the nuclear magnetic resonance instrument. This method solves the problem that the amount of sand produced is too small and difficult to monitor in the process of conventional sand production experiments, and explores the sand production law of formation more comprehensively from a microscopic point of view. Using this method, the influence of five factors such as flow velocity, production pressure difference, permeability, water content, and formation pressure drop on formation sand production is analyzed. The experimental results show that: 1) the higher the flow velocity, the core permeability and sand production volume; both increase first, then decrease, and finally remain unchanged; 2) the critical flow rate of H gas storage is 4.14 L/min, and the critical production pressure difference is 5 MPa; 3) the water cut and the formation pressure drop are affected by the pore size distribution, and are the main factors affecting sand production in H gas storage formation; 4) when H gas storage has no water production in the early stage, proper sand production will increase the permeability of the formation and increase the gas injection and production capacity of the gas well.

10.11885/j.issn.1674-5086.2021.10.19.03