Method and apparatus for extracting heavy oil

Abstract

A method and apparatus for extracting and producing heavy crude oil from subterranean oil fields is provided. The method utilizes a specially designed mixing mandrel to facilitate the combination and mixing of a high API gravity diluent with heavy crude oil from a subterranean oil reservoir, such that the resulting heavy oil mixture can be efficiently pumped to the surface.

What is claimed is: 
     
         1 . A well for use to extract oil from a subterranean oil field, the well comprising:
 a wellhead;   a production tube extending from the wellhead, the production tube having a bottom end defining a fluid entry point open to the subterranean oil field;   a mixing mandrel at least partially positioned within the production tube to form an annular space therebetween, wherein the annular space includes a spiral mixing spline positioned therein, wherein the annular space includes a radially extending baffle positioned therein, wherein the spiral mixing spline and the radially extending baffle extends radially outwardly from the mixing mandrel, and wherein the mixing mandrel is positioned downstream of the fluid entry point;   an injector port configured to inject diluent into the first tubing string, wherein the injector port is downstream of the fluid entry port; and   a pump configured to pump both the diluent and the oil to the well head, wherein the pump includes an inlet positioned downstream of the mixing mandrel.   
     
     
         2 . The well of  claim 1 , wherein the injector port is positioned upstream of the mixing mandrel. 
     
     
         3 . The well of  claim 1 , wherein the oil enters the production tube via the first entry point, and wherein the mixing mandrel is configured to receive oil and diluent therein and output an oil mixture. 
     
     
         4 . The well of  claim 3 , wherein the resulting oil mixture is, by volume, about 5-50% of the diluent. 
     
     
         5 . The well of  claim 3 , wherein the resulting oil mixture is, by volume, about 5-15% of the diluent. 
     
     
         6 . The well of  claim 3 , wherein the API gravity of the resulting oil mixture is at least 19° API or greater. 
     
     
         7 . The well of  claim 1 , wherein the API gravity of the diluent is at least 50° API. 
     
     
         8 . The well of  claim 1 , wherein the pump includes one of a rod pump, a progressive cavity pump, and a hydraulic pump. 
     
     
         9 . The well of  claim 1 , wherein the radially extending baffle is positioned downstream of the spiral mixing spline. 
     
     
         10 . The well of  claim 1 , wherein the spiral mixing spline extends at least 360 degrees circumferentially about the mixing mandrel. 
     
     
         11 . The well of  claim 1 , wherein the pump inlet is at least partially formed into the mixing mandrel. 
     
     
         12 . A mixing mandrel for use in a well having a production tube having a bottom end defining a fluid entry port open to a subterannean oil field, an injector port configured to inject diluent into the production tube, and a pump having an inlet, the mixing mandrel comprising:
 a body at least partially positionable within the production tube to form an annular space therebetween, wherein the body is positionable downstream of the fluid entry point, upstream of the pump inlet, and downstream of the injector port;   a spiral mixing spline extending radially outwardly from the body; and   a radially extending baffle extending radially outwardly from the body.   
     
     
         13 . The mixing mandrel of  claim 12 , wherein the radially extending baffle is positioned downstream of the spiral mixing spline. 
     
     
         14 . The mixing mandrel of  claim 12 , wherein the spiral mixing spline extends at least 360 degrees circumferentially about the mixing mandrel body. 
     
     
         15 . The mixing spline of  claim 12 , wherein the radially extending baffle is one of a plurality of radially extending baffles. 
     
     
         16 . The mixing spline of  claim 15 , wherein each radially extending baffle of the plurality of radially extending baffles is positioned downstream of the spiral mixing spline.