Texaco Inc.

Terry L Frazier

Donald S Mims

Alfred Brown

Alvin J Sustek, Jr

Richard S Allen

John F Rooney

Henry J Grimm

Jan D Dozier

Christopher M Lonvick

Gregory Daryl

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

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

A reciprocating type oil well pump. It employs modifications of standard pump structure in order to obtain a reverse flow pulse during each pumping cycle. The pump barrel has a port near the upper end of the stroke, and the traveling valve is spring loaded against a desired pressure. The piston closes the port during the lower portion of the stroke.

Reciprocating pump with partial flow reversal

A method for determining the quality of steam flowing in a line used for steam injection, e.g. in an oil well. It has a vertical loop in the line, with an orifice in the up-flow side. The pressure, temperature and pressure drop at the orifice are measured before and after injecting a stream of water upstream from the orifice. The water stream is injected at a constant flow rate, and its temperature and pressure are measured. Using the measurements before and after the introduction of the water stream, simultaneous equations are developed related to the mass flow rate and to the heat flow rate, so that the steam quality may be determined.

Method of measuring quality of steam in a flow fine

The disclosed invention is a method for analyzing the annulus effluent of a producing well in a steam flood and using the information derived therefrom to determine whether to workover the production well for greater production, whether to allow the well to continue producing 'as is', or whether to shut-in the annulus or the tubing production and approximately when the well should be worked over or shut-in.

Method for predicting workovers and shut-ins from analyzing the annulus

High viscosity petroleum, such as heavy oils and tar, is recovered by first drilling a number of production wells in a conventional pattern, then drilling a plurality directionally drilled injection wells extending radially inward toward each producing well, such that the surface location of each injection well is not less than the normal spacing between production wells, and the bottom hole location approaches the production well closely enough that fluid communication between the two wells can be established by the injection of heated fluids into the injection well. The petroleum is then recovered from the producing well by conventional thermal means.

Recovery method for high viscosity petroleum

Fluid injectivity within an interval in a well bore is determined by injecting into the well two fluid streams, one of which flows down the tubing and one of which flows down the annulus, one of said fluid streams containing a radioactive tracer. The sum of the two fluid flow rates is held constant while each flow rate is varied against the other. At each different pair of flow rates, a stable interface is formed between the fluid containing the radioactive tracer and the fluid without it. The position of this stable interface at each different set of fluid flow rates is measured by a conventional gamma ray well logging tool, and from the series of such measurements an injectivity log over the measured interval can be determined. The injectivity profiles for the two components of a two phase fluid flow system are determined by conducting the survey with a radioactive tracer soluble in the gas phase and repeating the survey with a radioactive tracer soluble in the liquid phase.

Method of injectivity profile logging for two phase flow

Fluid injectivity within an interval in a well bore is determined by injecting into the well two fluid streams, one of which flows down the tubing and one of which flows down the annulus, each of said fluid streams containing a different radioactive tracer. The fluid stream injected into the tubing contains a radioactive tracer that is soluble almost exclusively in the liquid phase of the fluid, while the annulus fluid stream contains a radioactive tracer soluble almost exclusively in the gas phase of the fluid. The sum of the two fluid flow rates is held constant while each flow rate is varied against the other. At each different pair of flow rates, stable interfaces will be formed between the gas phase in the tubing and the gas phase from the annulus as well as the liquid phase in the tubing and the liquid phase from the annulus. The position of these stable interfaces at each different set of fluid flow rates is measured by a conventional gamma ray well logging tool, and from the series of such measurements an injectivity log for both fluid phases over the measured interval can be determined.

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Paso Robles, CA, United States of America

Terry L Frazier