Granular Obstructing Agent for Horizontal Well Liner Integrity
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Solution Overview
Problem
In situ combustion processes for heavy oil and bitumen reservoirs face challenges due to the viscosity of cold hydrocarbons preventing heated hydrocarbons from reaching production wells, leading to combustion quenching and potential well failure from oxidant short-circuiting and liner erosion.
Innovation Solution
The process involves providing a horizontal production well with a permeable granular material obstructing agent in its section to prevent oxidant short-circuiting, ensuring a stable combustion front and hydrocarbon recovery by filling the horizontal section with highly permeable materials like granular sand or ceramic beads to create a uniform flow path for coke deposition and prevent liner failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a slotted liner is used in the horizontal section of the production well, then hydrocarbons can flow into the wellbore, but oxidant can short-circuit through the slots bypassing the combustion front
Solution Approach 1:
A permeable granular material is introduced as an intermediary substance within the slotted liner to mediate between the need for hydrocarbon entry and the need to prevent oxidant short-circuiting. The granular material fills the slots and allows hydrocarbon flow while restricting oxidant bypass, thus resolving the contradiction between productivity and combustion front stability
Solution Approach 2:
The patent utilizes porous granular material within the slotted liner structure. The porous nature of the granular material allows it to selectively permit flow based on pressure gradients and fluid properties, enabling hydrocarbon entry while preventing oxidant short-circuiting through the same slots
2Productivity
If the combustion front progresses through the reservoir, then hydrocarbons are heated and displaced, but coke deposition may be uneven or insufficient to seal the liner slots
Solution Approach 1:
The granular material is pre-installed in the slotted liner before combustion begins. This preliminary action ensures that the slots are already filled with a material designed to accept and distribute coke deposition uniformly, preventing the problem of uneven or insufficient sealing that would occur with bare slots
Solution Approach 2:
The patent changes the physical parameters of the liner interior by filling slots with granular material of specific size and permeability. This parameter change transforms the slot structure from a simple opening to a controlled porous medium that regulates flow and enhances coke deposition uniformity
3Reliability
If oxidant short-circuits through the liner slots, then combustion gases expand rapidly and cause liner failure, but preventing short-circuiting requires blocking the slots
Solution Approach 1:
The granular material creates a porous flow path that maintains liner integrity by preventing oxidant short-circuiting while preserving hydrocarbon productivity through selective permeability that allows oil flow
Solution Approach 2:
The granular material is placed locally within the slotted liner slots, creating a localized zone with different flow characteristics. This local modification prevents oxidant bypass at the slot level while maintaining overall hydrocarbon flow capability through the wellbore
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution stabilizes the combustion front, prevents well failure, and enhances hydrocarbon recovery by ensuring consistent flow and deposition of coke, thereby improving the efficiency and safety of in situ combustion processes.
Implementation Method 1
injecting an obstructing agent into the substantially horizontal section of the production well, wherein the obstructing agent is a highly permeable granular material
Implementation Method 2
injecting the oxidant into the injection well to establish a combustion front of ignited hydrocarbons within the underground reservoir
Implementation Method 3
The heat of combustion and the hot combustion products warm the portion of the reservoir adjacent to the combustion front and drives (displaces) the hydrocarbons toward offset production wells
Implementation Method 4
relies on the deposition of petroleum coke in the slots of a perforated liner in the horizontal section of the production wellbore
Data Source
AI summary
An underground reservoir is provided comprising an injection well and a production well. The production well has a horizontal section oriented generally perpendicularly to a generally linear and laterally extending, upright combustion front propagated from the injection well. The method relates to controlling location of inflow into a production well during in situ combustion. The horizontal section of the production well includes blocking agents to prevent well failure.