Texaco Inc.

Alvin J Sustek, Jr

Terry L Frazier

Alfred Brown

Wilbur L Hall

Henry J Grimm

Thomas G Scott

Thomas S Teasdale

John F Wiechel

Gregory Daryl

A method is disclosed for recovering hydrocarbons by a series of steps wherein about 0.1 to about 0.6 pore volumes of steam of a relatively high quality is initially injected into the formation. Thereafter, an additional 0.1 to about 0.6 pore volumes of steam is injected wherein the quality of the steam is gradually decreased to a relatively low quality. The injection sequence is concluded with about 0.5 to about 2.0 pore volumes of water, preferably at an ambient temperature.

Tapered steam injection process

The present invention is a sequenced method of increasing the injectivity of oil bearing formations and increasing hydrocarbon recovery. The method of the invention is initiated by injecting an aqueous fluid at an ambient temperature into the formation through an injection well while concurrently recovering fluid at a production well. The first injection stage is followed by the injection of fluid of gradually increasing temperature until a temperature of about 75.degree.-100.degree. C. is reached. Finally, steam is injected into the formation.

Varying temperature oil recovery method

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.

Continuous steam quality monitoring is obtained by bleeding the steam through an orifice to generate acoustic energy. An acoustic transducer is coupled to the wall that contains the orifice. And, an amplifier with a narrow band acoustic frequency filter is employed so as to produce an output signal having an amplitude that is proportional to the quality of the steam.

Growing community of inventors

Houston, TX, United States of America

Alvin J Sustek, Jr