Tool for removing fluids and loose material from an earth formation,申请号US19780922928-传众专利搜索

Tool for removing fluids and loose material from an earth formation

申请公布号：US4161985(A)

申请号：US19780922928

申请日期：1978.07.07

申请公布日期：1979.07.24

申请人：

DOW CHEMICAL CO THE

发明人：FOURNIER, ONAZIP J;NELSON, WAYNE F

分类号：E21B34/00;E21B34/10;E21B37/08;(IPC1-7):E21B37/00;E21B41/00

主分类号：E21B34/00

摘要：The tool of this invention is designed primarily for removing unconsolidated sand and other debris from the well casing perforations and adjacent earth formation in an oil or gas recovery operation. The basic tool includes an upper valve unit and lower valve unit, which are coupled together by a surge chamber. In a typical cleaning operation the tool is lowered into the well casing on a tubing string, which includes a by-pass and a retrievable packer. When the tool is at the desired position in the casing, the packer is set and the by-pass is closed. Fluid under pressure is pumped down the casing annulus to trip a mandrel in the lower valve and open a flapper disk. Bottom hole pressure causes fluid in the formation to fill the surge chamber and the sand and debris falls to the bottom of the hole. The packer is then unset and fluid pressure down the tubing string trips a piston in the upper valve and allows a stationary mandrel to open another flapper disk. The tubing string is then lowered to wash out the sand and debris in the hole by reverse circulation. After the formation has been cleaned the packer can be released and re-set to perform a further treatment, such as gravel packing, to achieve sand control.