| 摘要 |
The present invention relates to a downhole system for unloading a liquid of a well in an annulus between an intermediate casing and a production tubular metal structure. The downhole system comprises the intermediate casing; a pump at a top of the well, configured to pressurise the annulus to displace the liquid in the annulus; the production tubular metal structure having a first inner diameter, arranged partly in the intermediate casing, thereby defining the annulus; a production packer arranged between the intermediate casing and the production tubular metal structure, and a first liquid unloading assembly and a second liquid unloading assembly, each comprising a tubular part having a wall having a second inner diameter, an outer face and an aperture, the tubular part being configured to be mounted as part of the production tubular metal structure; and a check valve connected with the outer face, the check valve having an inlet in fluid communication with the annulus and an outlet in fluid communication with the aperture. The downhole system further comprises a sliding sleeve arranged to slide along an inner face of the tubular part between an open position and closed position to open or close the aperture. Furthermore, the present invention relates to a liquid unloading method for unloading liquid of a well in an annulus between an intermediate casing and a production tubular metal structure. |
