Perforation Optimization for Deep Tight Sandstone Fracturing
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Solution Overview
Problem
Hydraulic fracturing operations in deep and tight sandstone reservoirs face challenges due to high breakdown pressures, which can lead to premature operation termination and inefficient fracture propagation, especially when the wellhead pressure limits are exceeded.
Innovation Solution
A method and system that utilize diagenetic rock typing, flow index evaluation, and in-situ stress calibration to determine optimal perforation locations and directions, allowing for a calibrated breakdown pressure envelope, thereby selecting the most suitable perforation clusters to reduce the required breakdown pressure and ensure effective fracture propagation into better rock quality zones.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional perforation methods are used in deep and tight sandstone reservoirs, then the wellhead can provide sufficient pressure, but the breakdown pressure is too high causing premature operation termination
Solution Approach 1:
The patent applies local quality by selecting specific perforation locations at different depths along the wellbore based on evaluated rock properties. Different zones are identified with varying diagenetic rock typing and flow indices, allowing optimization of perforation placement in zones with lower breakdown pressures to ensure successful fracture initiation while managing overall pressure requirements.
Solution Approach 2:
The patent implements preliminary action through comprehensive pre-fracturing evaluation including diagenetic rock typing, flow index calculation, and in-situ stress calibration before the actual fracturing operation. This preliminary characterization allows determination of breakdown pressure envelopes and optimal perforation locations, enabling proactive pressure management during the fracturing process.
2Productivity
If perforation locations are selected without optimized evaluation, then the process is simpler, but fracture propagation becomes inefficient
Solution Approach 1:
The patent applies parameter changes by utilizing multiple evaluated parameters including diagenetic rock typing, flow index, and in-situ stress calibration results to determine breakdown pressure envelopes. These parameter variations guide the selection of optimal perforation locations and directions, enabling efficient fracture propagation through scientifically-based parameter optimization rather than trial-and-error approaches.
3Productivity
If the wellhead pressure limit is exceeded to achieve fracture propagation, then fractures can propagate, but the operation must be terminated prematurely
Solution Approach 1:
The patent implements preliminary action through pre-fracturing evaluation including diagenetic rock typing, flow index calculation, and in-situ stress calibration before the actual fracturing operation. This preliminary characterization allows determination of breakdown pressure envelopes and optimal perforation locations, enabling proactive pressure management during the fracturing process.
Solution Approach 2:
The patent applies local quality by selecting specific perforation locations at different depths along the wellbore based on evaluated rock properties. Different zones are identified with varying diagenetic rock typing and flow indices, allowing optimization of perforation placement in zones with lower breakdown pressures to ensure successful fracture initiation while managing overall pressure requirements.
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 enables the successful initiation of fractures at lower breakdown pressures, ensuring efficient hydraulic fracturing operations by optimizing perforation locations and directions, thus enhancing the economic production of hydrocarbons from deep and tight sandstone reservoirs.
Implementation Method 1
Hydraulic fracturing is a stimulation method that uses highly pressurized fluids to fracture the formation and increase the formation drainage areas
Implementation Method 2
A perforating gun is shot into the well to a target depth and perforations are created by detonating explosives
Data Source
AI summary
A method includes gathering data about the well and the deep and tight sandstone reservoir, evaluating a diagenetic rock typing and a flow index of the reservoir using the data, and determining a first set of perforation locations based on the diagenetic rock typing and the flow index. The method also includes calibrating in-situ stresses based on the data and determining a breakdown pressure envelope and optimal perforation directions using the in-situ stresses, maximum horizontal stress direction, formation mechanical properties, and well trajectory. The method further includes narrowing the first set of perforation locations to a second set of perforation locations based on the breakdown pressure envelope, comparing the breakdown pressure envelope of the second set of perforation locations to a maximum downhole pressure to determine a perforation method, and performing a fracturing operation on the well using the second set of perforation locations, the perforation method, and the optimal perforation directions.