Sand layer geology directional drilling crossing centering device

Abstract

The invention discloses a sand layer geology directional drilling crossing centering device, and belongs to the field of large diameter pipeline directional drilling crossing centering devices. The sand layer geology directional drilling crossing centering device at least comprises a mandrel, a connection sleeve, a float bowl, a support plate and water channels, wherein the float bowl is fixedly connected on the external diameter of the mandrel through the connection sleeve, the support plate and the water channels are arranged in the float bowl, and a reinforcing rib plate is arranged on the connection sleeve. According to the sand layer geology directional drilling crossing centering device, mud in a mandrel mud channel can be directly drawn forth from a plurality of water feeding holes in a plurality of water channel communication mandrels arranged in a front cone barrel and a rear cone barrel of the closed type float bowl, and passes through the plurality of the water channels formed in the front and the rear of the float bowl, floating force can be increased, dead weight of the sand layer geology directional drilling crossing centering device is balanced well, pressure intensity to a stratum is greatly reduced, and accordingly settlement quantity is decreased, not only is a well casing plumb line guaranteed, but also a well casing can not sink along with gravel due to gravel sinking, simplicity and safety of construction are improved, and quality of construction under a sand layer complexity geology condition is improved.

Description

technical field [0001] The invention relates to the field of centralizers for directional drilling of large-diameter pipelines, in particular to a centralizer for directional drilling of sand layer geology. Background technique [0002] Directional drilling crossing technology is widely used in oil and gas pipelines crossing rivers, ditches, highways, railways and other areas that are not easy or suitable for shallow buried passage. The limiting conditions of directional drilling crossing technology are mainly the crossing length, construction site and engineering geological conditions. [0003] At present, the caliber of oil and gas pipelines at home and abroad is getting larger and larger. During the directional drilling construction of large-diameter pipelines, centralizers are usually used in rock geological conditions. Centralizers are cementing tools and are installed outside the well pipe. The guiding device is used to ensure the quality of drilling and cementing; ho...

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Problems solved by technology

[0006] If the stratum in the crossing section is in complex geological conditions such as silt layer, silt layer or medium sand layer, because the stratum is relatively loose, with low water content and poor cohesion, it is easy to produce mud and difficult to form holes when directional drilling crosses, and the sand layer is easy to form grit pockets. Drilling, in addition to the large diameter of the crossing pipe, the number of reaming stages is large, the impact and disturbance on the formation is relatively large, and the possibility of hole collapse is increased, making the construction very difficult

[0007] In the process of lowering the pipe, due to the complex geological conditions of the large-diameter sand layer, the existing hob-type centralizers and pipe-ring centralizers cannot be used in the complex geological conditions of the sand layer. The well pipe cannot be placed in the center, the drill hole is inclined and bent, resulting in uneven gravel packing thickness, and the thin side of the gravel packing cannot block the fine particles in the silt and fine sand water-bearing formation, resulting in a large amount of sand production, which can neither guarantee the well pipe lead The sinking of the gravel caused the sinking of the well pipe, which made the construction in the complex geological conditions of the silt and fine sand layer fail to meet the quality requirements.

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