Research method of trajectory design and on-site tracking and adjustment of shale oil horizontal well
First Claim
1. A method for trajectory design and on-site tracking and adjustment of a shale oil horizontal well, comprising:
- step A;
identifying and evaluating shale oil sweet spots, comprising;
based on analytical and assay results of a system-cored well, carrying out research on a seven-property relationship among source rock, lithology, electrical property, physical property, brittleness, oil-bearing probability and earth stress, establishing a standard for geophysical response characteristics of a shale oil layers for a single well, and determining planar distribution of sweet spots;
Step B;
a “
four-optimal”
method for trajectory design of the shale oil horizontal well, comprising;
(1) optimal selection of a target area;
selecting a favorable exploration target area based on the thickness and buried depth of a shale oil sweet spot interval, and its coupling relationship with the degree of thermal evolution of shale;
(2) optimal selection of a target layer;
carrying out fine correlation of oil layers in the optimal target area, determining an optimal sweet spot interval based on the principles of a large oil layer thickness, stable distribution, a high drilling success rate of a known well, and easy identification of seismic characteristics in logging;
(3) optimal selection of a target direction;
comprehensively analyzing factors including attitude of stratum, fault influence, and fracture development direction of the determined target layer, and selecting an optimal drilling direction; and
(4) optimization of a trajectory;
carrying out fine seismic calibration, and further optimizing a horizontal well trajectory scheme based on a drilling direction determined by the optimal target direction to ensure a maximum drilling success rate of the optimal sweet spot interval;
Step C;
a “
two-fine”
method for tracking and adjustment of the shale oil horizontal well, comprising;
(1) fine analysis and accurate target entering;
during a drilling process, timely analyzing the accuracy of a stratum velocity and the reasonableness of a seismic interpretation scheme, and timely making adjustments to ensure precise target entering; and
(2) fine tracking to prevent off-target;
performing fine correlation according to comprehensive mud logging data and a logging-while-drilling curve, and correcting the trajectory to ensure the drilling success rate of a high-quality small layer.
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Abstract
The present invention discloses a research method of trajectory design and on-site tracking and adjustment of a shale oil horizontal well, including identification and evaluation of shale oil sweet spots, optimal selection and trajectory design of the horizontal well, and on-site tracking and adjustment of the shale oil horizontal well. The “four-optimal and two-fine” practice in the research method of trajectory design and on-site tracking and adjustment of the shale oil horizontal well of the present invention lays a foundation for high and stable production of shale oil in closed lake basins and the integration of production and reserves increase. It provides a set of technical methods for the design and research of optimal selection of horizontal well locations and dynamic tracking analysis of drilling in shale oil development areas, and has great significance for reference and popularization.
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Citations
8 Claims
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1. A method for trajectory design and on-site tracking and adjustment of a shale oil horizontal well, comprising:
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step A;
identifying and evaluating shale oil sweet spots, comprising;based on analytical and assay results of a system-cored well, carrying out research on a seven-property relationship among source rock, lithology, electrical property, physical property, brittleness, oil-bearing probability and earth stress, establishing a standard for geophysical response characteristics of a shale oil layers for a single well, and determining planar distribution of sweet spots; Step B;
a “
four-optimal”
method for trajectory design of the shale oil horizontal well, comprising;(1) optimal selection of a target area;
selecting a favorable exploration target area based on the thickness and buried depth of a shale oil sweet spot interval, and its coupling relationship with the degree of thermal evolution of shale;(2) optimal selection of a target layer;
carrying out fine correlation of oil layers in the optimal target area, determining an optimal sweet spot interval based on the principles of a large oil layer thickness, stable distribution, a high drilling success rate of a known well, and easy identification of seismic characteristics in logging;(3) optimal selection of a target direction;
comprehensively analyzing factors including attitude of stratum, fault influence, and fracture development direction of the determined target layer, and selecting an optimal drilling direction; and(4) optimization of a trajectory;
carrying out fine seismic calibration, and further optimizing a horizontal well trajectory scheme based on a drilling direction determined by the optimal target direction to ensure a maximum drilling success rate of the optimal sweet spot interval;Step C;
a “
two-fine”
method for tracking and adjustment of the shale oil horizontal well, comprising;(1) fine analysis and accurate target entering;
during a drilling process, timely analyzing the accuracy of a stratum velocity and the reasonableness of a seismic interpretation scheme, and timely making adjustments to ensure precise target entering; and(2) fine tracking to prevent off-target;
performing fine correlation according to comprehensive mud logging data and a logging-while-drilling curve, and correcting the trajectory to ensure the drilling success rate of a high-quality small layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification