Method and Apparatus to Isolate Well Pressure While Connecting Tubing to Tubing - J-Slot Type
Publication Date: 2015-Jul-16
The IP.com Prior Art Database
This paper describes a new apparatus and method for connecting two different types of work strings, in particular Jointed Tubing and Coiled tubing. The advantages of the method of using combined strings of Jointed Tubing and Coiled Tubing in the process of stimulating long horizontal oil wells are well known in the industry. The method is facilitated by a special Safety Valve installed between the two types of work strings. This valve protects personnel from well pressure while making up or braking down the connection between the two work strings.
The two basic components of this Safety Valve assembly are a Flapper Valve, and a Sliding Sleeve. The apparatus is operated by manipulating the Sliding Sleeve in two positions: (1) Sliding Valve retracted, allowing the Flapper Valve to check/stop any incoming fluid from the well formation; (2) Sliding Valve extended, holding the Flapper open and at the same time protecting it from erosion of the pumped fluid which is mixed with sand. The current equipment involves actuating this Safety Valve with hydraulic pressure either with a hand pump at the surface, or by placing the Safety Valve between two Blow Out Preventers (BOPs).
Description of the proposed improved design
The designed proposed in this paper is based on a Lug – J-Slot cam actuation type. The Figure 1 below is mostly self-explanatory. The Sleeve is installed with the Lug in the J-Slot such as to hold the flapper in open position. A fixed Screw can be inserted to lock it in that position. To close the Flapper, insert a Bar in a Lug or both Lugs. Then simply move the Sleeve in the Flapper –closed position. Another fixed Screw can be inserted in the Sleeve through a hole (not shown) in the Housing (shown in green) to lock the Valve assembly in the closed position. The J-slot shown is in a C-shape; alternatively a helical J-slot can be utilized as well. The open or closed position is positively visually indicated by the position of the Lug in the J-Slot.
Figure 1. Current and proposed design...