Offshore oil and gas field gathering and transmission pipe descaling and evaluation method

Abstract

The invention relates to an offshore oil and gas field gathering and transmission pipe descaling and descaling effect evaluation method, which comprises the following steps of: a, preparing a chemical tank; b, injecting neutral descaling agent in the chemical tank; c, detecting concentration of total calcium ions in water samples at the head end and the tail end of a gathering and transmission pipe by adopting an EDTA (ethylene diamine tetraacetic acid) titration method; d, starting up a chemical injection pump to pump the descaling agent into the head end of the gathering and transmission pipe; e, after the descaling agent is injected, periodically detecting the concentration of total calcium ions in the water samples at the head end and the tail end of the gathering and transmission pipe by continuously adopting the EDTA titration method; f, adjusting the input quantity of the descaling agent till the concentration of the total calcium ions in the water sample at the head end of the gathering and transmission pipe is obviously smaller than the concentration of the total calcium ions in the water sample at the tail end of the gathering and transmission pipe; g, conducting mechanical descaling by adopting a ball passing operation method; and h, when the concentration of the total calcium ions in the water sample at the head end of the gathering and transmission pipe is detected to be equal to the concentration of the total calcium ions in the water sample at the tail end of the gathering and transmission pipe, adjusting the concentration of the neutral descaling agent to a low value.

Description

technical field [0001] The invention relates to a method for descaling and evaluating the descaling effect of offshore oil and gas field gathering and transportation pipelines. Background technique [0002] At present, there are mainly mechanical methods and chemical methods for descaling oil pipelines in offshore oil fields. Mechanical descaling is descaling by means of drilling tools, special equipment and water flushing. This method of descaling is often incomplete and requires a lot of manpower. Chemical descaling is to use the descaling agent to dissolve or loosen the scale and easy to fall off by means of hydrothermal circulation or soaking. It has the function of thorough descaling, no damage to the scaling equipment, and the labor intensity of descaling is small, which is beneficial to the recovery of oil and gas wells. Production capacity and other advantages, has gradually developed into an effective descaling method. At present, the effect of descaling in oil f...

AI Technical Summary

Problems solved by technology

At present, the effect of descaling in oil fields can only be judged from a macro perspective. For example, if there is a lot of scale removed through the sea pipe ball operation, it means that the descaling effect is good, otherwise the effect is poor.

This method is time-consuming and laborious, and cannot accurately evaluate the descaling effect

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