Bottom hole assembly comprising flow through setting tool and frac plug

Abstract

A bottom hole assembly comprising a hydraulic setting tool, a frac plug, and usually also an adapter for connecting the frac plug to the setting tool. The setting tool, adapter, and frac plug, all include continuous flow passages that allow fluid to be circulated in the well ahead of the plug as the bottom hole assembly is advanced. This removes debris present in the well and prevents the frac plug from becoming lodged in the well in other than the desired location. The setting tool includes a bypass feature that signals reliably when the plug has been successfully deployed. The bypass assembly comprises sliding members with bypass ports that can become aligned only when the collar on the frac plug has advanced far enough to ensure complete deployment of the frac plug.

1 . A bottom hole assembly for connection to the end of a well conduit having a fluid flow passage therethrough, the assembly comprising:
 a frac plug having a downhole end and an uphole end and a flow passage extending therebetween for passing fluid through the plug;   a hydraulic setting tool having a downhole end and an uphole end and a flow passage extending therebetween for passing fluid through the tool;   wherein the uphole end of the frac plug is connected to the downhole end of the setting tool so that the flow passage in the setting tool is in fluid communication with the flow passage in the frac plug.   
     
     
         2 . The bottom hole assembly of  claim 1  further comprising an adapter for connecting the setting tool to the frac plug, wherein the adapter comprises a flow passage for passing fluid through the adapter. 
     
     
         3 . A method for setting a frac plug, comprising:
 flowing fluid through the frac plug as it is advanced down the well.   
     
     
         4 . A setting tool for use with a well conduit to activate a downhole tool, the downhole tool comprising a stationary member and a sliding member, the setting tool comprising:
 an upper housing assembly having an upper end, the upper end being connectable to a well conduit;   a piston mandrel assembly with an upper end connectable to the upper housing assembly and a lower end connectable to the stationary member of the downhole tool so as to prevent axial movement therebetween;   a slide assembly comprising a sleeve engageable with the sliding member of the downhole tool and slidably supported on the piston mandrel for movement relative thereto along a selected range of travel from a retracted position to an extended position, wherein the range of travel is sufficient to activate the downhole tool;   a hydraulic system configured to drive the movement of the slide assembly to complete the range of travel;   a bypass assembly comprising a plurality of ports movable between aligned and non-aligned positions, wherein in the aligned positions, the ports allow release of hydraulic fluid from the hydraulic system sufficient to produce a rapid and substantial pressure drop, wherein the bypass assembly is configured to align the ports when the sleeve in the slide assembly has completed the selected range of travel.   
     
     
         5 . The setting tool of  claim 4  wherein the setting tool is characterized by a flow passage extending therethrough and wherein the downhole tool is a frac plug with a flow passage extending therethrough that is continuous with the flow passage in the setting tool and with the conduit.