Sw-sagd with between heel and toe injection

Abstract

The present disclosure relates to a particularly effective well configuration that can be used for single well steam assisted gravity drainage (SW-SAGD), wherein steam injection occurs at one or more points between the heel and toe, instead of at the toe as in the prior art.

Description

PRIORITY CLAIM[0001]This application is a non-provisional application which claims benefit under 35 USC §119(e) to U.S. Provisional Application Ser. No. 62 / 153,269 filed Apr. 27, 2015, entitled “SW-SAGD WITH BETWEEN HEEL AND TOE INJECTION,” which is incorporated herein in its entirety.FEDERALLY SPONSORED RESEARCH STATEMENT[0002]Not Applicable.REFERENCE TO MICROFICHE APPENDIX[0003]Not applicable.FIELD OF THE DISCLOSURE[0004]This disclosure relates generally to methods that can advantageously produce oil using steam-based mobilizing techniques. In particular, it relates to improved single well gravity drainage techniques with better steam chamber development than previously available.BACKGROUND OF THE DISCLOSURE[0005]Oil sands are a type of unconventional petroleum deposit, containing naturally occurring mixtures of sand, clay, water, and a dense and extremely viscous form of petroleum technically referred to as “bitumen,” but which may also be called heavy oil or tar. Bitumen is so h...

AI Technical Summary

Benefits of technology

This patent proposes using variations in the location and number of steam injection points to improve oil recovery. The invention also involves using flow control devices to control flow in both producers and injectors. By controlling flow, the devices create higher drawdown pressures and higher flow rates along more resistant sections, correcting uneven flow caused by the heel-toe effect and heterogeneous permeability. Overall, this approach helps to improve the recovery performance of oil wells.

Problems solved by technology

The conventional SW-SAGD utilizing one single horizontal well to inject steam into reservoir through toe and produce liquid (oil and water) through mid and heel of the well has potential for thin-zone applications where placing two horizontal wells with 5 m vertically apart required in the SAGD is technically and economically challenging.

SW-SAGD, however, exhibits several disadvantages leading to slow steam chamber growth and low oil rate.

First of all, SW-SAGD is not efficient in developing the steam chamber.

Secondly, a large portion of the horizontal well length perforated for production does not actually contribute to oil production until the steam chamber expands over the whole length.

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