Search International and National Patent Collections
|1. (WO2018040138) SPIRAL-TYPE FLOW SEPARATION DUAL-WALL OIL TUBE FOR VOLUME FRACTURING OF HORIZONTAL WELL|
|Applicants:||CHINA NATIONAL PETROLEUM CORPORATION CHUANQING DRILLING ENGINEERING COMPANY LIMITED CHANGQING DOWNHOLE TECHNOLOGY COMPANY
|Title:||SPIRAL-TYPE FLOW SEPARATION DUAL-WALL OIL TUBE FOR VOLUME FRACTURING OF HORIZONTAL WELL|
Disclosed is a spiral-type flow separation dual-wall oil tube for volume fracturing of a horizontal well, the oil tube comprising an inner tube (3) and an outer tube (2), wherein the inner tube (3) is sheathed in the outer tube (2), a cavity is formed between the inner tube (3) and the outer tube (2), and two ends of the inner tube (3) are connected to the outer tube (2) via an upper coupling (1) and a lower coupling (4) respectively. An outer surface of the inner tube (3) is provided with a double spiral flow channel. By using a structure of the dual-wall tube with spirals outside the inner tube, the sand concentration, the flow rate and the pressure at an upper gun in a multi-stage dual cluster perforating fracturing string for the volume fracturing of the horizontal well are improved, the probability of excessive sand accumulation and flow rate at a lower gun are reduced, and the existing problems of sand deposition and sand-liquid separation in a horizontal section of a horizontal well as well as the non-uniformity of perforations of the upper and lower guns in the multi-stage dual cluster perforating fracturing string are effectively solved, thus increasing the success rate of multi-stage dragging and a dual cluster jet fracturing operation of the horizontal well.