Improved methods of propping a fracture in a subterranean zone whereby the subsequent flow-back of the proppant is prevented are provided. The methods basically comprise the steps of placing proppant and a magnetized material in said fracture while maintaining the fracture open and then allowing the fracture to close on the proppant and magnetized material whereby the magnetized material clusters in voids and channels in the proppant bed formed.
A high strength composite particle comprised of a series of incrementally applied resin microlayer coatings such that each of the microlayer partial coatings are interleaved with each other is described. Methods of making the composite particles, as well as methods of using such particles as a proppant in oil and gas well hydraulic fracturing are also described.
A method is given of fracturing a subterranean formation including the step of a) pumping at least one device actively transmitting data that provide information on the device position, and further comprising the step of assessing the fracture geometry based on the positions of said at least one device, or b) pumping metallic elements, preferably as proppant agents, and further locating the position of said metallic elements with a tool selected from the group consisting of magnetometers, resistivity tools, electromagnetic devices and ultra-long arrays of electrodes, and further comprising the step of assessing the fracture geometry based on the positions of said metallic elements. The method allows monitoring of the fracture geometry and proppant placement.
Methods for the treatment of subterranean wells involving injecting a first fracturing fluid into a formation, and then injecting at least a second fracturing fluid into the formation in order to create extended conductive channels through a formation are described. The fracturing fluids can be similar in density, viscosity, pH and the other related characteristics. Alternatively, the fracturing fluids can differ in their densities, viscosities, and pH, allowing for variations in the conductive channels formed. Propping agents can also be included in one or both of the injected fluids, further enhancing the conductive channels formed. The described methods aid in minimizing proppant flowback problems typically associated with hydraulic fracturing techniques.
An increase in effective propped lengths is evidenced in hydraulic fracturing treatments by the use of ultra lightweight (ULW) proppants. The ULW proppants have a density less than or equal to 2.45 g/cc and may be used as a mixture in a first proppant stage wherein at least one of the proppants is a ULW proppant. Alternatively, sequential proppant stages may be introduced into the formation wherein at least one of the proppant stages contain a ULW proppant and where at least one of the following conditions prevails: (i.) the density differential between the first proppant stage and the second proppant stage is greater than or equal to 0.2 g/cc; (ii.) both the first proppant stage and the second proppant stage contain a ULW proppant; (iii.) the rate of injection of the second proppant stage into the fracture is different from the rate of injection of the first proppant stage; or (iv.) the particle size of the second proppant stage is different from the particle size of the first proppant stage.