Abstract: Two spaced apart zones of a carbonate containing formation are simultaneously acid fractured. A lower density fracturing acid is injected into an upper zone of the formation via an annulus of a perforated wellbore communicating with the upper zone thereby causing a fracture to propagate. Simultaneously therewith, a higher density fracturing acid is injected into a lower spaced apart zone via a tube within the wellbore which fluidly communicates with the lower zone thereby causing simultaneously the propagation of a second fracture. Neither fracture contacts the other although complete fracture growth and zonal acidizing is obtained.

Abstract: A well completion process for improved cement placement in a horizontal wellbore where a fluid is circulated down the wellbore for conditioning and cleaning it. Afterwards, a production tube containing centralizers is positioned centrally within the wellbore. Next, a "spacer fluid" is circulated within an annulus formed by the space between the tube and the wellbore so as to clean the annulus out. Subsequently, a cement having a density greater than the spacer fluid is pumped into the annulus. Thereafter, a light weight cement is pumped into the annulus thereby overriding the heavier cement and removing voids in the annulus resulting in more efficient cement placement.

Abstract: A process to temporarily seal an upper zone of higher permeability. Coiled tubing is used to cover a zone of lower permeability with a gel block containing rock salt. A lower density, more stable, slower yielding gel block having a gel breaker is squeezed into the upper zone. The well is shut-in and the low density gel plug becomes rigid. Water is then circulated down the coiled tubing to dissolve the high density gel block out of the wellbore and re-open lower perforations which allows the low permeability interval to be treated.

Abstract: A process where massive hydraulic fracturing (MHF) is used in combination with a novel horizontal and vertical well drilling scheme. The novel well drilling scheme provides the cost benefits of vertical drilling along with the increased pay zone contact of extended-reach drilling. MHF additionally provides for substantially enhanced reservoir drainage.

Abstract: A method for improved matrix acidizing of a sandstone formation containing a perforated well. Initially, a "pre-pad" and a temperature stable viscous gel pad are pumped into the formation via said well at injection pressures greater than 5 BPM while monitoring surface pressures. Next, an acid suitable for acidizing the formation is pumped into the formation while the injection pressure is maintained. Thereafter, additional stages of viscous pad and acid are pumped into the formation to ensure zonal coverage and acid-stimulation.

Abstract: A method for simultaneously matrix acidizing two spaced apart zones of a carbonate containing formation. Initially, a lower density acid is injected into an upper zone of said formation hereby forming wormholes which make this zone more permeable. Simultaneous with the injection of the lower density acid, a higher density acid is injected into a lower spaced apart zone of said formation at a pressure sufficient to simultaneously form wormholes within said lower zone thereby acidizing each zone simultaneously. Thereafter, a solidifiable viscous gel with gel breakers is directed into the upper and lower zones which gel enters the wormholes and forms a solid gel therein which precludes entry of additional acid while displacing the acid further into the formation. Subsequently, additional acid is introduced into the upper and lower zones which acid bypasses the wormholes containing the solid gel and penetrates substantially further thereby substantially increasing the permeability of the formation.

Abstract: A method to reduce water coning in viscous oil formations during primary oil production wherein a horizontal wellbore is heated by circulating steam therein thereby heating a radial area near the wellbore. Near wellbore heating alters a pressure profile in the radial area near the wellbore. Reduced inflow pressure gradients near the wellbore flatten out a pressure sink associated with the wellbore. This reduces substantially water coning which allows more oil to be produced before high water production begins.

Abstract: A method for replacing a damaged or corroded casing with a solid plastic is described herein. After removing the corroded or damaged casing from the wellbore, the borehole is underreamed to a desired diameter. Thereafter, a resin/curing agent mixture sufficient to form a hardened plastic or resin able to withstand downhole stresses, is placed into the wellbore so as to bind with the undamaged casing and close off any thief zone. Subsequently, the resin/curing agent mixture forms a hardened solid. The hardened solid is milled out so as to form a resinous casing the size of the original casing. Later, the hardened resinous casing is perforated to communicate with a targeted zone. Perforation is not required when isolating a zone.

Abstract: An improved method for removing organic residue from ZSM-18 which can be used during zeolite synthesis or with an as-synthesized ZSM-18. When used during synthesis, a minute amount of noble metal is incorporated into the ZSM-18. Alternatively, a noble metal-containing precursor is impregnated onto as-synthesized ZSM-18. Thereafter, ZSM-18 united with the noble metal is reduced in hydrogen at 200.degree. C. for about 1 hour. Next, ZSM-18 united with the noble metal is calcined at 300.degree. C. for 10-24 hours, and subsequently at 500.degree. C. for 1-3 hours thereby producing a ZSM-18 material that is free of organic residue.

Abstract: A method and composition for removing barium and strontium sulfate scale deposits. The composition comprises an aqueous solution having a pH of about 8 to about 14, an EDTA or DTPA chelant, and a catalyst or synergist. Preferred chelants comprise diethylenetriaminepentaacetic acid (DTPA) or ethylenediaminetetraacetic acid (EDTA or alkali salts thereof. Anions of organic and inorganic acids comprise the catalyst. Catalysts which can be used include fluoride, oxalate, persulfate, dithionate, hypochlorite and formate anions. When the solution containing the composition is contacted with a surface containing a scale deposit, the deposit dissolves substantially more scale quicker than heretofore possible.

Abstract: This invention is directed to a method for recovering residual oil from produced fines and solid materials which are obtained during the production of viscous oil from a formation. The fines and produced materials are injected into a formation with or without fracturing for their disposal. Once in the formation, a non-thermal enhanced oil recovery method is used to remove residual oil from the fines or solid materials. Use of this method provides an inexpensive and environmentally safe method for recovering residual oil from formation fines or solids.

Abstract: A method and composition for controlling the profile of a formation where temperatures higher than 400.degree. F. are encountered. An aqueous solution of an organoammonium silicate, alkali metal or ammonium silicate is injected into a zone of higher permeability in a formation. Subsequently, a spacer volume of a water-immiscible organic solvent is directed into said zone. Afterwards, a water-miscible organic solvent containing an alkylpolysilicate and an inorganic salt or a chelated calcium compound are injected into the higher permeability zone. A silicate cement is formed in-situ thereby substantially closing the higher permeability zone to fluid flow. Thereafter, a steam-flooding, water-flooding, carbon dioxide-flooding, or fire-flooding EOR operation is commenced in a lower permeability zone.

Abstract: This invention is directed to a method to improve fracture acidizing in a carbonate containing formation. Initially, the formation is hydraulically fractured so as to form a fracture in the formation in a preferred direction. Thereafter, an acid is directed into the fracture so as to etch the fracture's face and create channels therein. Afterwards, a viscous fluid is directed into the fracture which fluid contains a material sufficient to serve as a diverter and prevent growth in the existing fracture. Once the diverting material is in place, hydraulic fracturing is again conducted within the existing fracture whereupon fracturing forces are directed away from the diverter so as to form a branched fracture to contact hydrocarbonaceous vugs in the formation. The steps of fracturing acidizing, and diverting are continued until a vuggy area in the formation has been interconnected with the fracture system.

Abstract: A method for disposing of drilling wastes where an aqueous saline solution is used to disperse a drilling fluid or mud. The saline solution containing the dispersed drilling fluid or mud is injected into a disposal well or high permeability oil depleted zone. An interval of the formation adjacent to the disposal well is hydraulically fractured so as to allow continued injection of the solution containing the drilling fluid or mud at substantially low pressures. Hydraulic fracturing is used to re-establish communication with a disposal zone whenever a "skin" builds up due to filtration of the solids from the injected drilling fluids or muds.

Abstract: A method for gravel packing a wellbore where a resin-coated sand or "gravel" is utilized. First, the wellbore is perforated at the productive interval in a manner sufficient to hydraulically fracture the formation. Afterwards, the formation is hydraulically fractured via a frac fluid containing a resin-coated sand. During this fracturing operation, a resultant fracture is propped with the resin-coated sand. The frac fluid is pumped down the wellbore until "screen out" occurs at perforations in the wellbore. The resin-coated sand is allowed to remain in the fracture, perforations, and wellbore until a permeable, porous consolidated mass is formed. After the mass has formed, excess consolidated sand is removed from the wellbore. When the formation is produced, formation solids are contained by the consolidated mass in the fracture and perforations.

Abstract: A method for controlling the profile of a formation where temperatures higher than 400 degress F. are encountered. An aqueous solution of potassium silicate is injected into a zone of greater permeability in a formation. Afterwards, an alcoholic solution of hydrated calcium chloride is injected into the greater permeability zone. Calcium silicate is formed in-situ thereby substantially reducing the permeability of the higher permeability zone. Thereafter, a steam-flooding or fire-flooding operation is commenced in a lower permeability zone.

Abstract: A method for forming a gravel pack in a washed-out interval is provided where a borehole penetrates an unconsolidated or loosely consolidated oil or gas reservoir which is likely to introduce substantial amounts of sand into the borehole. After perforating the borehole's casing at a washed-out interval of the formation, sand is introduced into the interval. Afterwards, an aqueous solution of potassium silicate is injected into said interval. Thereafter, an alcoholic solution of hydrated calcium chloride is injected into the interval. A permeability retaining calcium silicate cement is formed in the interval thereby making a gravel pack. Injection of the potassium silicate and hydrated calcium chloride solutions is continued until the porosity of the interval has been reduced by the calcium silicate cement to an extent sufficient to exclude formation fines and sand.

Abstract: A method and device for removing sand from hydrocarbonaceous fluids whereby a berm is formed adjacent to a slot which has penetrated a liner or perforated tube. The berm which is formed along each side of said slot operates to form a lip or platform so as to provide a solid base upon which to form a sand bridge to more effectively remove sand from hydrocarbonaceous fluids produced from the well.

Abstract: A method and composition for removing barium and strontium sulfate scale deposits. The composition comprises an aqueous solution having a pH of about 8 to about 14, an EDTA or DTPA chelant, and a catalyst or synergist. Preferred chelants comprise diethylenetriaminepentaacetic acid (DTPA) or ethylenediaminetetraacetic acid (EDTA) or alkali salts thereof. Anions of organic and inorganic acids comprise the catalyst. Catalysts which can be used include Fluoride, oxalate, persulfate, dithionate, hypochlorite and formate anions also thio, amino, and hydroxy acetate anions. When the solution containing the composition is contacted with a surface containing a scale deposit, the deposit dissolves substantially more scale quicker than heretofore possible.

Abstract: A sand consolidation method is provided for use in a borehole having an unconsolidated or loosely consolidated oil or gas reservoir which is likely to introduce substantial amounts of sand into the borehole and cause caving. After perforating the borehole's casing at an interval of the formation where sand will be produced, an aqueous solution of potassium silicate is injected into said interval. Thereafter, an alcoholic solution of hydrated calcium chloride is injected into the interval. A permeability retaining calcium silicate cement is formed in the interval. Injection of the potassium silicate and hydrated calcium chloride solutions is continued until the interval has been consolidated by the calcium silicate cement to an extent sufficient to prevent sand migration and thereby prevent caving.