Texaco Inc.

Alfred Brown

Ching H Wu

Wilbur L Hall

Wann-Sheng Huang

Yick-Mow Shum

Joseph C Allen

Donald S Mims

Terry L Frazier

Ralph J Korstad

Henry J Grimm

Daniel T Konopnicki

Lawrence E Whittington

Mohan V Kudchadker

Margaret A Hight

Stephen L Long

Richard S Allen

James E Varnon

Charles D Woodward

John F Rooney

Yin L Cheung

Issam S Bousaid

Russell D Shupe

Jack H Park

Stewart Haynes, Jr

Thomas W Norman

Jeffrey T Hawkins

Alvin J Sustek, Jr

Marc F Fontaine

Donald L Hoyt

Zean Z Gassmann

Yick M Shum

Frank H Lim

Charles R French

Stephen F Hager

Richard A Deans

Moutaz Chichakli

Gerald W Alves

Christopher M Lonvick

Joseph H Frantz

Brian L Reynolds

A potassium salt which is soluble either in water or in an oil-based drilling mud is forced via filtrate invasion into permeable subsurface formation zones adjacent a well borehole via an over-balanced drilling mud or completion system. Well logging is then performed in an interval of interest in the formations using natural gamma ray spectrometry. Gamma radiation at an energy of 1.46 MeV from the naturally occurring radioactive potassium isotope .sup.40 K is detected. Gamma radiation levels of the isotope .sup.40 K above normal background readings indicate the presence of permeable formations.

Method of delineating naturally fractured intervals in subterranean

Our invention concerns a method for treating a well completed in a subterranean petroleum containing formation which will improve the rate at which steam can be injected into the formation for a steam push-pull or steam drive oil recovery method. This preconditioning process is applied to formations exhibiting very limited steam receptivity because the formation contains high oil viscosity and has high oil saturation and is completely liquid filled. The method involves injecting a heated non-condensable and oil soluble gas all in the gaseous phase into the formation at a controlled rate which will avoid permanently fracturing the formation and also avoid the immediate formation of an oil bank due to dissolution of the injected gaseous fluid into the oil. Ideally by controlling the injection rate, carbon dioxide first displaces water from the flow channels and then slowly dissolves in the oil. Steam injection can then be applied to the formation without the previously experienced loss in steam injectivity.

Viscous oil recovery method

An oil recovery process employing a well pattern having a horizontal well located along each of the four sides of a substantially rectangular well pattern, a vertical injection well located at the center of the well pattern, and four vertical infill wells located midway between the central injection well and the four corners of the rectangular well pattern. Steam is initially injected through the central injection well and production taken at the four infill walls. After the injection of about 0.5 to about 1.0 pore volumes of steam through the central injection well, central injection is converted to water, the infill production wells are converted to steam injection, and production is taken from the horizontal wells.

Steamflood process employing horizontal and vertical wells

The disclosed invention is an apparatus for analyzing the annulus effluent of a producing well. The apparatus is designed to measure the flow rate of the annulus effluent, sample the annulus effluent and determine the quantities of each of the various phases of the annulus effluent. The apparatus is preferably mounted on a mobile vehicle and comprises a means for measuring the flow rate of the annulus effluent, a liquid vapor separator to split the annulus effluent into streams of entrained liquid and vapor, a separator to split the entrained liquid into the phases of oil and water, a sampling loop for extracting a sample of annulus effluent vapor which contains a condensor and a separator for splitting the fluid into its various phases, a means for measuring the amounts of all of the phases of the annulus effluent, and a means to record the data gathered. The apparatus is very useful in determining whether a producing well should be shut-in, worked over or left to produce 'as is'.

Apparatus for analyzing the annulus effluent of a well

The invention is a well pattern containing at least one substantially horizontal production well approximately located on and parallel to an axis running between two substantially vertical production wells with the horizontal well having a length equal to about 30% to about 60% of the distance between the two vertical production wells.

Patterns having horizontal and vertical wells

A method and/or apparatus for determining the mass flow rate and the quality of steam in a flowing line. It involves directing the total flow to a liquid-vapor separator. The separated vapor and liquid have the flow of each metered and the flow of one regulated so as to hold the level of the separated liquid constant. Then, by measuring pressure and temperature of the separated flows upstream from the regulation, the mass flow rate and the quality of the steam may be determined.

Method and apparatus for determining mass flow rate and quality in a

The disclosed invention is a method of producing horizontal wells in the most efficient manner at an optimum fluid production rate, which is the maximum rate at which fluids may be produced from a horizontal well while maintaining the downward velocity of formation fluids towards the horizontal well at a velocity which will avoid fingering of the fluids through the formation.

Optimum production rate for horizontal wells

A method for recovering petroleum from a subterranean petroleum formation penetrated by at least one well in fluid communication with the formation, by a cyclic carbon dioxide injection procedure comprising injecting carbon dioxide into the well followed by a soak period, followed by a production of oil from the formation, wherein the improvement comprises introducing a predetermined quantity of hydrocarbon such as high API gravity crude oil, naphtha, kerosene, gasoline or aromatic solvent which will remain liquid at the temperature of the formation into the formation immediately after introducing the carbon dioxide slug and before the soak and production steps, to dissolve high molecular weight fraction of the crude oil left in the flow channels of the formation, which are recovered from the formation in the production phase. The volume of solvent use is sufficient to fill the well and saturate the formation for a distance of from 4 to 10 feet into the formation.

Carbon dioxide stimulated oil recovery process

A method applicable to secondary recovery procedure employing an injection well. It applies to conditions caused by return flow of injection fluid back into the well from the formation being injected. It frees the well and injected formation from heavy paraffinic-aromatic residue that is carried by the return flow.

Secondary recovery procedure

The disclosed invention is a method of recovering hydrocarbons by determining the critical concentrations of various crude oil components to carbon dioxide to achieve first contact miscibility of a mixture of said crude oil components and carbon dioxide with the underground hydrocarbons at formation temperature and a selected pressure substantially lower than first contact miscibility pressure of carbon dioxide with the hydrocarbons; injecting into the formation a premixed transition zone slug comprising carbon dioxide and said crude oil components at said critical concentrations, formation temperature and said selected pressure; and injecting a drive fluid into the formation after the premixed transition zone slug.

Carbon dioxide flooding with a premixed transition zone of carbon

The disclosed invention is a method of injecting steam foaming agents in conjunction with steam and usually, a non-condensable gas into production wells producing a substantially high water to oil ratio. The most preferred production wells for foaming agent injection are corner production wells of flooding patterns such as inverted 5- and 9-spots, especially when the flooding pattern contains infill wells between the central injection well and the corner production wells. Although the method of injecting foaming agent, steam and usually, a non-condensable gas is effective with any foaming agent, the method works particularly well with foaming agents of the general formula:

Injection of steam foaming agents into producing wells

A well completion and the method therefor for a wellbore which extends generally horizontally of a subterranean layer comprised primarily of unconsolidated sand particles which hold a viscous hydrocarbon. The completion includes an elongated perforated liner which is positioned in the wellbore. The liner is substantially surrounded by a gravel pack which functions to limit the amount of sand particles which are carried from the subterranean layer into the liner in response to the introduction of a flow of a hot stimulating fluid into the substrate.

Method and apparatus for gravel packing horizontal wells

Method for forming a gravel pack in-situ about a horizontal well in a sandy formation. The gravel pack is formed in two separate steps so that part of the pack will function as a foundation for slidably inserting and supporting the well liner. Thereafter, the remainder of the pack is completed about the liner by introducing a gravel slurry that accumulates on the foundation and about the liner.

Method for forming a gravel packed horizontal well

Method and apparatus for obtaining a sample of the liquid component of steam and determining the quality of steam in a vessel or the like, such as steam flowing in a line used for steam injection in an oil well. The steam quality is determined by the known method of comparing the concentrations of dissolved solids in the liquid sample and the feedwater. A sample of the liquid phase of steam is trapped in a liquid vapor separator maintained at steam line temperature and pressure conditions. In this way errors due to condensation in the separator and its connecting lines are avoided. The sample is withdrawn from the separator into a collection chamber at a controlled rate which avoids reducing the pressure within the separator and thereby avoids the introduction of error because of erroneous concentration of dissolved solids within the separator sample. Errors are avoided also which in other methods and devices are introduced by the difficulty of obtaining representative two-phase samples and by deposition of solids in throttling orifices.

Method and device for measuring steam quality

Method for producing viscous hydrocarbon products such as heavy crude oil or bitumen from tar sands, which products must be thermally converted into flowable condition. A discrete vertical subsection of a productive subterranean layer is marginated by a pair of spaced apart vertical wells and a horizontal well that lies substantially horizontal to the vertical wells. Controlled, pressurized flows of a heating medium such as steam are introduced to one of the vertical wells and to the horizontal well, whereby to establish a controlled thermal front. The latter is progressively urged by the pressurized steam, through the discrete vertical subsection and toward the other of the vertical wells at which hydrocarbon emulsion is produced.

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Houston, TX, United States of America

Alfred Brown