Abstract
On average each well within the Barnett Shale play will produce from five (5) to ten (10) horizontal zones. Each zone is perforated and fractured with between 500,000 and 1,000,000 gallons of slickwater prior to isolation in order to repeat the process on the next zone. Previous to the methodology further described within this paper, the composite material frac plugs were deployed into the horizontal section of the wellbore by means of electric wireline and a tractoring system. While proving successful, this system did have limitations with respect to time and ultimately economics especially considering the average number of zones per well that required temporary isolation.
This paper will describe a system method improvement being utilized by most operators in the play whereby a Hydraulic Pump-Down Frac Plug is utilized. This cased hole temporary plug can be ‘displaced’ into the well at speeds of up to 200 feet-per-minute with surface pump rates of less than 10 barrels-per-minute. The BHA that is run consists of the Hydraulic Pump-Down Frac Plug, Wireline Adapter Kit, Wireline Pressure Setting Assembly, 2 sets of perforating guns and a firing head. After successful isolation and fracturing, the plugs are removed from the well bore in an under balanced environment by means of a coiled tubing milling assembly. The plugs have also been removed by reversing units utilizing 2-7/8" tubing and a 4-3/4" 5-bladed concave mill.
This paper will show how the development and use of this methodology has greatly increased the efficiency of completions within the Barnett Shale play by a potential reduction in time of 50% depending on the zone depth. The client costs have been significantly reduced not just in terms of time savings but also when the removal of the requirement for electric wireline with tractoring systems is taken into account.
