Downhole Casing Auger for Paraffin Removal in Non-Flowing Wells
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Solution Overview
Problem
Existing methods for removing paraffin deposits from oil and gas wells, such as knifing and hot-oiling, are inefficient, dangerous, and costly, and require the well to be flowing or pumping, making them unsuitable for wells with marginal reservoir pressure.
Innovation Solution
A casing auger with a longitudinal member and spiral flights that can cut and lift paraffin out of the wellbore without melting it, allowing operation when the well is not flowing, and optionally using fluid injection to loosen or dissolve the paraffin.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If hot-oiling is used to melt paraffin deposits, then paraffin removal is achieved, but operational safety deteriorates due to explosion risks from pressurized propane tanks and open burners
Solution Approach 1:
The patent replaces the thermal melting process (hot-oiling) with a mechanical cutting process. The auger tool mechanically cuts and removes paraffin deposits through rotational motion and cutting edges, eliminating the need for hot oil injection and associated explosion risks from pressurized propane tanks and open burners.
Solution Approach 2:
The patent extracts the paraffin removal function from the thermal process and implements it through a dedicated mechanical auger tool. The auger is inserted into the wellbore and rotates to cut and lift paraffin deposits, separating the removal operation from the hazardous hot-oiling process.
2Productivity
If knifing is used to cut out paraffin chunks, then paraffin removal is achieved, but operational time deteriorates as the process takes weeks to complete
Solution Approach 1:
The patent introduces dynamic rotational motion to the paraffin removal process. The auger rotates continuously or intermittently, enabling rapid cutting and lifting of paraffin deposits throughout the wellbore, transforming the static, time-consuming knifing process into a dynamic operation that completes removal in hours rather than weeks.
Solution Approach 2:
The auger enables continuous paraffin removal through sustained rotational action. Unlike knifing which requires repeated insertion and extraction operations, the auger can rotate continuously to cut and lift paraffin throughout the wellbore, maintaining useful action without interruption and significantly reducing total operation time.
3Productivity
If hot-oiling is used to melt paraffin, then paraffin cake is removed, but formation damage occurs and lighter and heavier hydrocarbons separate causing remaining paraffin to become harder
Solution Approach 1:
The patent replaces the chemical-thermal process of hot-oiling with a purely mechanical cutting process. The auger mechanically cuts paraffin deposits without introducing hot oil that would cause hydrocarbon separation and paraffin hardening, nor does it require temperatures that could damage the formation.
Solution Approach 2:
The patent converts the harmful effect of hot oil causing paraffin hardening into a benefit by using cold mechanical cutting. The auger cuts paraffin in its original state, avoiding the unwanted side effects of hot oil while achieving complete removal of the paraffin cake.
4Productivity
If augers are used to clear paraffin from tubing, then paraffin removal is achieved, but the well must be flowing under its own pressure which does not work for wells with marginal reservoir pressure
Solution Approach 1:
The patent designs the auger to be universally applicable to both flowing and non-flowing wells. The mechanical cutting action of the auger does not depend on well flow or reservoir pressure, making it versatile enough to operate in wells with marginal pressure where traditional flow-dependent methods fail.
Solution Approach 2:
The auger is driven by the drilling string rotation rather than requiring well flow to power the removal operation. The mechanical energy from the drilling string directly drives the auger cutting action, making the system self-sufficient and independent of well flow conditions or reservoir pressure.
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
Efficiently removes paraffin deposits without damaging the formation or downhole equipment, reducing operational risks and costs by enabling quick and safe removal even in non-flowing wells.
Implementation Method 1
rotating the apparatus to cut and dislodge paraffin from the paraffin cake with the plurality of flights
Implementation Method 2
injecting a fluid into the paraffin cake through the apparatus, wherein the fluid is selected to loosen, melt, or dissolve the paraffin cake
Data Source
AI summary
An apparatus and method for removing paraffin from a casing in a borehole of an oil/gas well without using pressure from the well. The apparatus may include a shaft with a plurality of flights wound around the shaft in a spiral pattern. The apparatus may include a coupling on one end for attachment to a drilling string. The method may include lowering the apparatus into the casing down to a paraffin cake lodged in the borehole. The apparatus may be used dislodge paraffin using the flights to cut the paraffin, an end of the apparatus, impact the paraffin, or both. Then the dislodged paraffin may be collected on the flights and lifted out of the casing for disposal.