Compositions and methods are given for plugging of natural or artificially-created fractures in subterranean formations to reduce the flow of fluids. The compositions are mixtures of primarily inert particles of different sizes that leave a minimal flow path for fluids when the particles are packed in the fracture. If the fracture can close on the particles, the particles need not fill the width of the fracture before closure to cause plugging.
A material and method for treating a fractured formation penetrated by a wellbore includes providing a quantity of resin coated particles having a particle size of from about 0.2 mm to about 2.35 mm. A quantity of smaller deformable or non-deformable particles is combined with the resin coated particles to form a generally uniform consolidated particle pack when mixed together and subjected to at least one of heat and pressure. A slurry of the particles is formed with a carrier fluid capable of suspending the particles. The slurry of particles is introduced into the wellbore of the formation. The resin coated particles and smaller deformable particles thus may form a consolidated particle pack in at least a portion of the fractures of the formation.
Degradable material assisted diversion (DMAD) methods for well treatment, DMAD treatment fluids, and removable plugs for DMAD in downhole operations. A slurry of solid degradable material is injected into the well, a plug of the degradable material is formed, a downhole operation is performed around the plug diverter, and the plug is then degraded for removal. Degradation triggers can be temperature or chemical reactants, with optional accelerators or retarders to provide the desired timing for plug removal. In multilayer formation DMAD fracturing, the plug isolates a completed fracture while additional layers are sequentially fractured and plugged, and then the plugs are removed for flowback from the fractured layers. In DMAD fluids, an aqueous slurry can have a solids phase including a degradable material and a fluid phase including a viscoelastic surfactant. The solids phase can be a mixture of fibers and a particulate material.
A method of improving injectivity of fluid, particularly produced water, in enhanced hydrocarbon recovery is disclosed. The method includes introducing a fracturing fluid into the subterranean formation to create a fracture, and introducing proppant into the fracturing fluid to form a single layer of proppant in the fracture. The fracturing fluid can be formed from produced water. Alternatively, the produced water is introduced after a fracturing fluid, other than the produced water, has been introduced to create a fracture. By reducing the amount of proppant and by using much larger proppant, a larger flow path through the fracture is created, thereby increasing the injectivity of produced water.
A method of propping at least one fracture in a subterranean formation is provided, the method comprising: forming a plurality of fly ash aggregates, each fly ash aggregate comprising an aqueous component and fly ash; introducing the plurality of fly ash aggregates into the at least one fracture; and curing at least a portion of the fly ash aggregates into at least one hardened mass. Also provided are methods of fracturing a subterranean formation and methods for the downhole formation of proppant particulates.
The present invention provides variable density fluid compositions and methods for using such compositions in a subterranean formation. One exemplary embodiment of the variable density fluid compositions of the present invention comprises a variable density fluid comprising: a base fluid, and a portion of variable pressure weighting material particles.
