Rock debris separating method for gas drilling

Abstract

The invention discloses a rock debris separating method for gas drilling. The rock debris separating method for gas drilling comprises the steps of firstly enabling water in a whole system to circularly flow to achieve balance and beginning to perform gas drilling; mixing gas and solid with the water to form a mixed fluid to enable dust in the solid to be dissolve in the water during drilling and before the gas returned from a well mouth and the solid are separated; enabling the mixed fluid to firstly flow into a primary separation system to remove coarse particles, discharging the gas carried with fine particles, water drops or water mist into a secondary separation system; removing the fine particles, water drops or water mist so as to obtain purified gas and a solid-liquid mixture after water bath washing is performed; delivering the solid-liquid mixture to a circulating water treatment system, and separating the coarse particles through primary treatment separation; removing the fine particles through secondary treatment separation; removing fine particles through tertiary treatment separation. The rock debris separating method for gas drilling can achieve returned fluid treatment under the condition that a grit chamber does not exist through gas drilling, gas meeting the direct emission standard is finally obtained, and the gas drilling requirement under different conditions can be met.

Description

technical field [0001] The invention relates to a cuttings separation method for gas drilling, which is used for separating the gas-solid-liquid mixed fluid returned from the wellhead during the gas drilling process, and replaces the existing gas drilling dust reduction method. Background technique [0002] In recent years, gas drilling technology has become increasingly mature, and its application scale has been continuously expanded, and it is actively developing into reservoir application. However, under the current technical conditions, the cuttings returned by gas drilling can only be separated by dust-fall water, and the outlet of the sand discharge pipeline must be connected to the sewage tank. If the gas is released from the formation, there is no ignition condition; , cuttings are easy to accumulate, affecting the subsequent use of the combustion pool. In addition, the dust reduction effect of the existing dust reduction method is not ideal, and the dust and wa...

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Problems solved by technology

But this patent also has the following deficiencies: 1. Since the patent uses the principle of cyclone separation to remove particulate matter in the fluid, in order to ensure the separation effect, the capacity of the cyclone separator should not be too large, resulting in generally less gas processing capacity, so It cannot meet the current ubiquitous gas drilling cuttings separation operation under large volume conditions. Second, because the solid phase content in the fluid returned from gas drilling is extremely high, this patent uses a vacuum pump for liquid transportation and discharge, and the liquid contains a large amount of For solid phase particles, the stability of the vacuum pump to deal with liquids containing high solid phase particles is not high enough, so this patent cannot meet the continuous operation of gas drilling cuttings separation under long-term conditions

3. Due to the unknown formations drilled by gas drilling, situations other than those predicted by geological data may occur. At present, gas drilling often encounters unexpected formation water production. The formation water production has a strong randomness and cannot be accurately predicted. When the formation is drilled When the water comes out, the patent does not state whether it is possible to continue the gas drilling cuttings separation operation

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