Wellbore Influx Detection Using Density and Temperature
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Solution Overview
Problem
Current early kick detection systems in wellbore drilling face challenges in detecting gas influxes due to gas expansion occurring too deep underwater, hydrate formation masking density changes, and the difficulty in distinguishing between drilling fluids and hydrocarbon influx, leading to false alarms and delayed detection.
Innovation Solution
A method using multiple pressure transmitters and temperature sensors to calculate and compare expected and actual densities of return flows, predicting hydrate formation, and adjusting for frictional pressure drops, allowing for early detection of wellbore influxes and preventing false alarms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If volume control-based kick detection is used, then early gas influx detection is possible, but detection accuracy deteriorates when hydrates form because the displaced volume is reduced by approximately 50%
Solution Approach 1:
The patent changes the detection parameter from volume flow (which is affected by hydrate formation reducing displaced volume) to density measurement. By measuring density changes in the return flow using Coriolis meters, the system can detect hydrate formation and gas influx accurately regardless of volume displacement issues.
Solution Approach 2:
The patent replaces the mechanical/volumetric detection system with a density-based detection system using Coriolis meters. This substitution allows the system to detect mass flow and density changes rather than relying on volume flow, which is compromised when hydrates form and reduce displaced volume.
2Ease of operation
If traditional volume control methods are used, then simple detection is achieved, but false alarms occur when light hydrocarbons are displaced with heavier drilling fluid (swap out)
Solution Approach 1:
The patent changes from volume-based detection to density-based detection. During swapout operations, even though volume flow may show changes, the density measurement provides reliable information about the actual fluid composition, allowing the system to distinguish between swapout conditions and actual gas influx.
Solution Approach 2:
The system uses density measurements as feedback to continuously monitor return flow characteristics. This feedback mechanism allows the system to adapt to changing drilling conditions including swapout operations, preventing false alarms by providing real-time density information that reflects actual influx conditions.
3Measurement precision
If multiple pressure transmitters and temperature sensors are deployed, then detection accuracy is improved, but device complexity increases
Solution Approach 1:
The patent employs Coriolis meters that serve multiple functions: they measure density, mass flow rate, and can detect hydrate formation. This multi-functionality reduces the need for separate dedicated sensors for each parameter, thereby managing system complexity while maintaining comprehensive detection capabilities.
Solution Approach 2:
The patent combines density measurement and mass flow measurement into a single Coriolis meter system. By merging these measurement functions into one device rather than using separate sensors, the system reduces overall device complexity while providing accurate detection of both parameters simultaneously.
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
Enables accurate and timely detection of wellbore influxes, reducing the risk of hydrate plugs and gas migration, and providing corrective actions to prevent incidents, by differentiating between drilling fluids and hydrocarbon influxes.
Implementation Method 1
calculating an expected density of a return flow between the at least one first pressure transmitter and the at least one second pressure transmitter by measuring or predicting a mud or sacrificial fluids density, a rock density, a first flow rate, a true vertical depth, a rate of penetration, and a wellbore diameter; continuously measuring an actual density of the return flow based on a measured pressure at each of the at least one first pressure transmitter and the at least one second pressure transmitter
Implementation Method 2
predicting a probability of hydrates forming in the well by using at least one first temperature transmitter arranged in a section of the well adjacent to the at least one first pressure transmitter and/or adjacent to the at least one second pressure transmitter, measuring a temperature at the at least one first temperature transmitter
Implementation Method 3
Hydrates may also form if the pressure is high and temperature low enough, making early kick detection based on volume control almost impossible. This is due to the fact that when hydrates have been formed, the gas or hydrates will not expand until the hydrates 'melt'. The gas molecules are 'trapped and/or hidden' within a crystal structure of water molecules
Implementation Method 4
the gas will be released and will expand rapidly, see details in FIG. 1
Data Source
AI summary
A method for detecting an influx in a wellbore with first and second pressure transmitters arranged in a fixed vertical distance in relation to each other. The method includes calculating an expected density of a return flow between the first and second pressure transmitters, continuously measuring an actual density of the return flow based on a measured pressure at the first and second pressure transmitters, comparing the calculated expected density of the return flow and the measured actual density of the return flow to determine the influx in the wellbore, and predicting a probability of hydrates forming in the well by measuring a temperature via a temperature transmitter arranged in a section of the well adjacent to the first and/or the second pressure transmitter, and using the temperature together with the measurements from the first and second pressure transmitters.