A Method for Determination of Internal Anticorrosion and Anode Protection Spacing for Coated Wells with Casing

Abstract

The invention discloses a method for determining the internal anti-corrosion anode protection interval of a casing inner coating well. The invention combines the inner anti-corrosion anode distribution of the casing according to different well depths, different well fluid salinity and different inner coating integrity rates, and combines indoor The installation mode of the sacrificial anode inside the casing is determined by means of simulation experiments, which avoids the technical complexity of field tests, reduces the cycle and times of indoor experiments, and avoids repeated experiments caused by different fluid media and casing inner coating integrity rates for each oil well To determine the anode distribution parameters. The experiment of the invention is fast and easy, the technology is reliable, and the economy is good.

Description

technical field [0001] The invention relates to the field of oil field corrosion and protection, in particular to a method for determining the distance between internal anti-corrosion and anode protection of casing inner coating wells. Background technique [0002] At present, the oil well pipe strings of oilfield production enterprises generally use ordinary carbon steel pipes, and the oil well production fluid will seriously corrode the carbon steel casing. In order to carry out oilfield development safely and efficiently, various oilfields generally adopt a variety of casing anticorrosion measures in addition to resistant pipes, such as external anticorrosion of impressed current cathodic protection, which is applied earlier and has mature technology, and epoxy cold wrapping tape (ring Oxygen coating) sacrificial anode anticorrosion, commonly implemented corrosion inhibitor filling technology, etc. In recent years, the cathodic protection technology of sacrificial anode b...

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Problems solved by technology

None of the existing patent documents has any discussion on the anode installation and arrangement method of the sacrificial anode in the casing. The distribution and installation of the sacrificial anode in the casing cannot be determined during production. The design experience of pipelines and storage tanks is determined

[0004] Due to the limited range of electromagnetic action of the sacrificial anode in the limited space of the oil well casing, and the depth of the oil well casing is more than one thousand meters underground, it is naturally difficult to measure the protection potential of the sacrificial anode in the casing. The method is to use the reference electrode fixed on the oil pipe to measure the potential of different positions on the inner wall of the casing. Anode distribution; if the protection potential and spacing distribution of sacrificial anodes in any wellbore environment are simulated indoors, the workload will be too large, time-consuming, labor-intensive and costly

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