Shale gas horizontal well geosteering method

Abstract

The invention discloses a shale gas horizontal well geosteering method. The method includes following steps: according to lithological and electric characteristics of a target stratum, performing stratigraphic division on the target stratum, and determining and contrasting a marker stratum; on the basis of three-dimensional after-stack time migration and pre-stack time migration data, utilizing a Geoframe interpretation system for human-computer interactive interpretation in a workstation, and performing precise tracking contrast on the target stratum to realize morphological structure of each stratum; adjusting A target track; geosteering a horizontal section, wherein in the process of real drilling of the horizontal section, stratum inclination angle along a track direction usually changes, while drilling data need to be collected timely, a gas stratum and the marker stratum to determine current real drilling position, track needs to be monitored in real time, prediction needs to be performed in advance, and directional construction needs to be guided to ensure the drilling track to pass within a designed stratum range. The shale gas horizontal well geosteering method is simple to operate, easy to master and needless of special professional instrument and equipment.

Description

technical field [0001] The invention relates to shale gas development technology, in particular to a geosteering method for a shale gas horizontal well. Background technique [0002] A horizontal well is a well with a well inclination at or close to 90°. The wellbore is drilled along the horizontal direction for a certain length of well. Sometimes the inclination can exceed 90°. The purpose of a horizontal well is to increase the exposed area of ​​oil and gas layers. The horizontal well greatly increases the contact area between the water collection structure and the gas in the unsaturated zone of groundwater and underground oil and gas, effectively improves the extraction efficiency of the fluid, and leads to a substantial increase in the production of the horizontal well. Therefore, the penetration of horizontal wells in the reservoir is the basic condition to ensure production, and the application of geosteering technology enables on-site technicians to correctly grasp th...

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Problems solved by technology

[0003] At present, on-site trajectory tracking technology methods at home and abroad are mainly divided into four types: one is based on companies such as Schlumberger and BakerHughes, each of which has its own on-site trajectory guidance software, which is convenient and fast, but is mainly suitable for relatively stable lateral The second is to realize on-site tracking through seismic data volumes, which mainly depends on the accuracy of seismic data, but the lack of reservoir concept makes the operation

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