Research on the Designing and Experimental Performance Evaluation of a New Sand Control Screen for Argillaceous Fine Silt Gas Hydrate Reservoirs

Argillaceous fine silt hydrate reservoirs have a clay content of 20–25% and a median sand particle size of 10–15 um. Sand control is extremely difficult, restricting the continuous and stable testing of gas hydrate. This paper focuses on the sand production mechanisms, plugging characteristics, and clogging mechanisms of these hydrate reservoirs. Based on the actual characteristics of hydrate reservoirs, it presents an understanding of the sand production mechanism of argillaceous fine silt. The characteristics and properties of three different sand control methods and six kinds of sand control screens are analyzed. Clear design concepts for sand control screens in argillaceous fine silt hydrate reservoirs are proposed. Two types of new sand control screen with metal filter screens and pre-filled screens have been innovatively designed, and the sand control ability and overflow performance of the screens are evaluated using the meter production index conversion method. Sand production simulation and comprehensive experimental evaluation and analysis of the flow performance of seven kinds of screens (themselves from two categories of screens) were carried out using a self-made special experimental testing device. The experimental results show that the newly designed screens have good flow performance and can meet the requirements of a certain gas production rate. Specifically, Class A metal screens (60/70 mesh) and Class B pre-filled screens (40/70 mesh) have excellent sand control capacity and flow performance, with 10 g sand output and 300 L total water output, thus fulfilling the sand control requirements and achieving the purpose of “effective sand control, prevention without plugging, and continuous stable production” of argillaceous fine silt gas hydrate reservoirs. They therefore provide a reference for future research on sand control and new screen designs for argillaceous fine silt hydrate reservoirs.