NMR Formation Tool Inducing Flow for Saturation Measurement
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Solution Overview
Problem
Current methods for assessing and producing hydrocarbon-bearing formations face challenges in accurately determining hydrocarbon and water saturations, residual oil saturation, and relative permeability, especially in complex carbonate environments, due to contamination from drilling fluids and uncertainties related to the drilling process.
Innovation Solution
A tool is introduced that generates a sensing field within a rock formation, allowing for fluid injection or withdrawal to create a flow, enabling measurements of hydrocarbon and water saturations, residual oil saturation, and relative permeability, using NMR and other sensing technologies to analyze changes in fluid states before and after flow induction, thereby reducing contamination effects and improving accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional logging methods are used to measure formation parameters, then basic formation data can be obtained, but measurement precision deteriorates due to contamination from drilling fluids and drilling process uncertainties
Solution Approach 1:
The system performs preliminary actions by establishing fluid communication and inducing flow before taking measurements. By creating controlled flow conditions and allowing the formation to respond, the system measures parameters under dynamic conditions that are less susceptible to contamination effects, thereby improving measurement precision
Solution Approach 2:
The system changes the state parameter of the formation by inducing flow through fluid injection or withdrawal. This transforms static formation conditions into dynamic flow conditions, allowing measurements to be taken under controlled flow regimes that reduce the impact of drilling fluid contamination on measurement accuracy
2Measurement precision
If fluid injection or withdrawal is performed to induce flow for measurements, then measurement precision improves by reducing contamination effects, but device complexity increases due to additional tools and operations required
Solution Approach 1:
The system combines multiple functions into a single integrated tool assembly that can both induce flow through fluid injection/withdrawal and perform NMR measurements. This multi-functional approach improves measurement precision while minimizing the increase in device complexity by consolidating operations rather than adding separate independent systems
Solution Approach 2:
The system merges the flow induction mechanism with the NMR measurement tool into an integrated assembly. By combining these functions in a single tool that can establish fluid communication and simultaneously or sequentially perform measurements, the system achieves improved precision without proportionally increasing overall device complexity
3Measurement precision
If NMR measurements are performed on stationary fluid in the reservoir rock, then basic formation fluid parameters can be obtained, but measurement precision deteriorates due to contamination and inability to distinguish bound and free fluids accurately
Solution Approach 1:
The system performs preliminary flow induction before NMR measurements to create dynamic conditions that allow differentiation between bound and free fluids. By establishing flow first, the system prepares the formation state to enable more accurate subsequent measurements of fluid distribution and properties
Solution Approach 2:
The system transitions from measuring stationary fluid to measuring fluid under dynamic flow conditions. This dynamic measurement approach allows the system to distinguish between bound and free fluids based on their different flow behaviors, thereby improving measurement precision and preventing loss of information about fluid states
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 approach allows for more precise determination of hydrocarbon and water saturations, residual oil saturation, and relative permeability, enhancing the estimation of recoverable reserves and the effectiveness of enhanced oil recovery (EOR) treatments by monitoring fluid composition changes and flow dynamics within the formation.
Implementation Method 1
NMR measurements are commonly used in the wellbore to probe the NMR decay behavior of the stationary fluid in the reservoir rock. During these measurements, magnetic fields are established in the formation using suitably arranged magnets. The magnetic fields induce nuclear magnetization, which is flipped or otherwise manipulated with on-resonance radio frequency (RF) pulses.
Implementation Method 2
These parameters can be derived from measurements of spin-spin relaxation time, often referred to as T2, spin-lattice relaxation time (T1), and self-diffusion coefficient (D) of the molecules containing hydrogen contained in formation fluids.
Implementation Method 3
These parameters can be derived from measurements of spin-spin relaxation time, often referred to as T2, spin-lattice relaxation time (T1), and self-diffusion coefficient (D) of the molecules containing hydrogen contained in formation fluids.
Implementation Method 4
a device for causing a flow through the measuring volume, possibly in the presence of the sensing field
Data Source
AI summary
Measuring a parameter characteristic of a formation in an oil well with a device configured to generate a sensing field within a volume of the formation and cause a flow through the volume in the presence of the sensing field. The device also comprises sensors responsive to changes in the volume, which indicate existent amounts of fluid, such as hydrocarbon and water saturations and irreducible hydrocarbon and water saturations. Measurements may be made before the flow affects the measuring volume and after onset of the flow through the measuring volume.