Evaluation of Multi-stage Fracturing by Hydrajet, Swellable Packer, and Compressive Packer Techniques in Horizontal Openhole Wells

Abstract

Horizontal openhole wells are commonly fractured by one of the three hydraulic fracturing techniques of hydrajet, swellable parker and compressive packer techniques. The paper reviews the application of 23 wells fractured by hydrajet (12 wells), swellable parker (4 wells) and compressive packer (7 wells) in tight gas sands in China. None method is overwhelming in the view of increasing production rate from the paper.The paper presented that different treatment pressures among stages may not a signal of perfect isolation. Created traverse fracture by hydraulic stimulation may not be at the middle of two packers or at the place of opened sleeve port for swellable packer and mechanical packer stimulation. Hydrajetting is a good choice to stimulate a specific place along the entire wellbore. Unlike in vertical wells, hydrajetting may not reduce the breakdown pressure in horizontal well treatment.The presented comprehensive comparison and discussion of the three fracturing methods will help operators understand the three methods better and accomplish production goals.

Elastic leak of a seal

“…Elastic deformation is of central significance to the leak of seals. For instance, in oilfields elastomers are widely used to block fluids, e.g., for testing rocks (Weinheber and Vasques 2006), completing boreholes (Noguera, Sierra et al 2009), and preparing boreholes for multi-stage hydraulic fracture (Mu, Ma et al 2012). In contrast to many other applications, the sealing conditions in oilfields cannot be fully determined before operation.…”

“…Engines require seals to enable gas-tight, reciprocating motion of pistons in cylinders (Flitney 2007). Hydraulic fracture requires seals to isolate fluids in gaps between pipes and boreholes (Yakeley, Foster et al 2007;Davis and McCrady 2008;Evers, Young et al 2008;Mu, Ma et al 2012). Seals, along with tires and bearings, are among the most significant applications of elastomers (Gent 2012).…”