Abstract: A method of enhancing the flow of hydrocarbon fluids from small flow conduits (12) in a subterranean reservoir rock formation (10) that have traditionally not been propped in association with a fracturing treatment of the formation (10), the method including the steps of introducing a first pressurized fluid into the formation at a pressure that is sufficient to expand the pre-existing small flow conduits (12) and introducing into the pressure-expanded small flow conduits (12) a first portion of a relatively small particulate propping agent (16); simultaneously with the fracturing of the formation, or immediately thereafter, introducing a second portion of a relatively small particulate propping agent (16) into expanded pre-existing small flow conduits and into any new small flow conduits that are formed by the fracturing of the formation; and reducing the hydraulic pressure on the formation, whereby the small flow conduits are held open by propping agent particles.

Abstract: Aqueous liquid compositions for increasing the permeability of a subterranean formation are disclosed, the compositions being characterized by provision of fluoborate anion (fluoboric acid) and a specified compound or compounds, or mixture thereof, which chelate aluminum ions and aluminum fluoride species. Methods of treating a subterranean formation by injection of the composition(s) into the formation are also described.

Abstract: The improved recovery of hydrocarbons from subterranean formations by hydraulically fracturing a subterranean formation is accomplished. Fracturing fluids using a viscosifying surfactant fluid containing viscosifying micelles, for example, wormlike micelles, are useful to improve recovery of hydrocarbons and limit the loss of fracturing fluid into the formation fracture face. The invention further relates to novel fracturing and acidizing methods useful for increasing hydrocarbon production, limiting water production, resisting fracturing fluid loss into the subterranean formation, and reducing the equipment requirements in mixing and pumping fracturing fluid. The action of viscosifying micelles of surfactant in aqueous zones of the subterranean formation diverts fracturing fluid or acid from the aqueous zones to the hydrocarbon-bearing zones and also facilitates the flowback of increased amounts of hydrocarbons once a fractured well is placed back on production.

Abstract: The improved recovery of hydrocarbons from subterranean formations by hydraulically fracturing a subterranean formation is accomplished. Fracturing fluids using a viscosifying surfactant fluid containing viscosifying micelles, for example, wormlike micelles, are useful to improve recovery of hydrocarbons and limit the loss of fracturing fluid into the formation fracture face. The invention further relates to novel fracturing and acidizing methods useful for increasing hydrocarbon production, limiting water production, resisting fracturing fluid loss into the subterranean formation, and reducing the equipment requirements in mixing and pumping fracturing fluid. The action of viscosifying micelles of surfactant in aqueous zones of the subterranean formation diverts fracturing fluid or acid from the aqueous zones to the hydrocarbon-bearing zones and also facilitates the flowback of increased amounts of hydrocarbons once a fractured well is placed back on production.

Abstract: The improved recovery of hydrocarbons from subterranean formations by hydraulically fracturing a subterranean formation is accomplished. Fracturing fluids using a viscosifying surfactant fluid containing viscosifying micelles, for example, wormlike micelles, are useful to improve recovery of hydrocarbons and limit the loss of fracturing fluid into the formation fracture face. The invention further relates to novel fracturing and acidizing methods useful for increasing hydrocarbon production, limiting water production, resisting fracturing fluid loss into the subterranean formation, and reducing the equipment requirements in mixing and pumping fracturing fluid. The action of viscosifying micelles of surfactant in aqueous zones of the subterranean formation diverts fracturing fluid or acid from the aqueous zones to the hydrocarbon-bearing zones and also facilitates the flowback of increased amounts of hydrocarbons once a fractured well is placed back on production.

Abstract: Aqueous liquid compositions for increasing the permeability of a subterranean formation are disclosed, the compositions being characterized by provision of fluoborate anion (fluoboric acid) and a specified compound or compounds, or mixture thereof, which chelate aluminum ions and aluminum fluoride species. Methods of treating a subterranean formation by injection of the composition(s) into the formation are also described.

Abstract: The improved recovery of hydrocarbons from subterranean formations by hydraulically fracturing a subterranean formation is accomplished. Fracturing fluids using a viscosifying surfactant fluid containing viscosifying micelles, for example, wormlike micelles, are useful to improve recovery of hydrocarbons and limit the loss of fracturing fluid into the formation fracture face. The invention further relates to novel fracturing and acidizing methods useful for increasing hydrocarbon production, limiting water production, resisting fracturing fluid loss into the subterranean formation, and reducing the equipment requirements in mixing and pumping fracturing fluid. The action of viscosifying micelles of surfactant in aqueous zones of the subterranean formation diverts fracturing fluid or acid from the aqueous zones to the hydrocarbon-bearing zones and also facilitates the flowback of increased amounts of hydrocarbons once a fractured well is placed back on production.

Abstract: Conductivity damage is decreased in fracturing a high temperature (greater than 200.degree. F.) well by employing a first fracturing fluid which is substantially stable at the bottom hole static temperature and pumping a second fracturing fluid behind the first fracturing fluid which is less stable at bottom hole static temperature than the first-pumped fracturing fluid.

Abstract: The permeability of the prop pack in a subterranean fracture containing a propping agent is improved by contacting the propping agent with fluoboric acid. The fluoboric acid slowly forms hydrolysis products, including hydrofluoric acid and hydroxyfluoboric acid, which react with and stabilize clays and other fines in the prop pack, thereby improving its permeability. Because the fluoboric acid hydrolyzes slowly, it can be injected deep into the fracture extremities before significant spending of the acid occurs.

Abstract: The permeability of a siliceous formation is increased by injecting in sequence, a fluoboric acid solution followed by a mud acid (HCl/HF) solution. The method is particularly advantageous in formations which have a tendency to plug initially upon contact with mud acid, or with HCl commonly used as a preflush ahead of mud acid. When contacted initially with fluoboric acid, such formations show little or no plugging effects when subsequently treated with mud acid.

Abstract: The permeability of a subterranean formation is increased by injecting into the formation, a conventional mud acidizing solution (HCl/HF) followed by a fluoboric acid solution. Use of fluoboric acid as an overflush is believed to deter clay migration and thereby significantly reduce or delay production decline which is often otherwise encountered shortly after conventional mud acidizing treatments.