Horizontal well deflecting section trajectory optimization method based on stratum thickness change

Abstract

The invention discloses a horizontal well deflecting section well trajectory optimization method based on stratum thickness change. The method comprises the following steps that 1, multi-well logginginformation is finely compared, lithofacies and stratum thickness change characteristic parameters are analyzed; 2, the stratum calibration is carried out on the seismic data according to the analysisresult of the multi-well logging information in the step 1, then the seismic data are finely processed, and the thickness and structure change rule of a target stratum series is found out; 3, well logging and seismic data results are combined, a thickness abnormal layer in the deflecting section is found out, and the stratum thickness variation and the burial depth variation range of the thickness abnormal layer are determined; 4, small-layer subdivision is carried out on the interior, the upper layer and the lower layer of the thickness abnormal layer in the deflecting section according to the electrical identification marks, and the electrical identification marks are arranged; and 5, risk well trajectory design is carried out, and an optimized drilling scheme is proposed. According tothe method for optimizing the well trajectory under the condition that the stratum thickness of the deflecting section of the horizontal well changes, a design thought and an operation method are provided, and a practical favorable tool is provided for high-quality landing of a horizontal well.

Description

technical field [0001] The invention belongs to the technical field of geosteering while drilling in well drilling engineering, and in particular relates to a trajectory optimization method for a deflection section of a horizontal well based on formation thickness changes. Background technique [0002] Oil and gas exploration and development rely more and more on horizontal wells to increase oil and gas production. Practice has proved that horizontal wells can greatly increase single well oil and gas production, while high-yield horizontal wells rely heavily on reservoir drilling ratio and drilling engineering quality. During the implementation of horizontal well drilling, due to the complexity and variability of downhole formations, abnormalities such as lithofacies changes, formation thickness changes or buried depth changes are often encountered, and formation thickness changes are the most common phenomenon. When this happens, It is easy to lead to difficulties in stratu...

AI Technical Summary

Problems solved by technology

During the implementation of horizontal well drilling, due to the complexity and variability of downhole formations, abnormalities such as lithofacies changes, formation thickness changes or buried depth changes are often encountered, and formation thickness changes are the most common phenomenon. When this happens, It is easy to lead to difficulties in stratum landing (advance or delay) and complex trajectory of the build-up section. If not handled properly, it will cause chain engineering complexity or even engineering accidents, which poses a challenge to the effective implementation of horizontal well drilling, and is also an urgent problem in horizontal well drilling engineering. one of the problems

[0003] Since this problem involves two fields of geology and drilling engineering, it is difficult to solve it. The current method mainly proposes a method to improve the accuracy of seismic processing to accurately predict the thickness of the formation. However, due to the limited seismic resolution and the influence of various factors Constraints often make it difficult to provide accurate data

The technical method of stabilizing the top of the slope is also proposed. This method assumes how to control the well trajectory under the assumption that the formation is thickened. However, if the formation change cannot be predicted, the trajectory is still difficult to control, so it lacks operability.

Some researchers also proposed to strengthen the identification and judgment of small layers to track and analyze, which has certain auxiliary value for early prediction during the actual drilling process, but how to establish a relationship with trajectory control needs to be explored. If the identification of small layers is difficult, it will be difficult to play a role

Therefore, the above method still has great limitations in guiding the steering of the horizontal well and realizing the smooth landing of the deflection section of the horizontal well, and it is even more difficult to realize the optimization of the well trajectory

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