A process and device for overall up-to-standard treatment of drilling waste in oil and gas fields

Abstract

The invention discloses a process and a device for overall standard-reached treatment for oil-gas field drilling waste. The process comprises the following steps of: (1) gel breaking and destabilization and solid-liquid separation treatment; (2) micro-nano bubble air-floatation oil removal treatment; (3) Fe / C electrolysis catalytic oxidation; and (4) polyhydroxy advanced oxidation deep treatment. According to the process and the device disclosed by the invention, the drilling waste is totally treated to reach the standard or partially reused for preparing mud, and a solid phase (sludge and drillings), a liquid phase (drilling wastewater), chloride ions (salts) and the like are completely treated to reach the standards; the leachate generated after the treatment for the solid phase (sludge and drillings) and the treated liquid phase (drilling wastewater) reach Class A of 'Integrated Wastewater Discharge Standard' for discharge to be discharged; the chloride ions in the drilling wastewater reach 'Standards for Irrigation Water Quality' (GB5084-92) after the treatment. Meanwhile, the treatment process flow is simplified, the wastewater is recycled, and energy consumption is saved.

Description

Technical field [0001] The invention relates to a process and device for processing drilling waste, in particular to a process and device for the overall standard-compliant processing of drilling waste in oil and gas fields. Background technique [0002] Drilling operations in oil and gas fields are a highly polluting industry, and the main pollutants come from waste drilling fluid and drilling cuttings. The main characteristics of these pollutants are high suspended solids SS, high water-soluble COD value, high chloride ion (salt) content, high chroma, and difficult treatment. At present, it is extremely difficult for domestic and foreign processes to meet emission standards. It restricts the sustainable development of my country's drilling industry. [0003] At present, drilling waste treatment technology is very backward, and still stays at the "three-step method". There are many shortcomings such as single technology, backward technology, incomplete degradation of pollutants, a...

AI Technical Summary

Problems solved by technology

Although a small number of oil and gas fields are processed by centralized combined stations or integrated devices, these processing equipment and devices are backward in technology, and most of the devices are actually a combination of several traditional coagulation, stirring and sedimentation filtration equipment. It is extremely inconsistent with each other, and there are many defects such as mismatch between chemical performance and equipment performance, water quality and equipment mismatch, and application conditions. Generally, it is difficult to treat the waste generated in shallow well operations up to the standard. It is even more difficult to dispose of complex drilling fluid waste in the sulphur-mud system

Moreover, these treatment devices almost only focus on the disposal of the solid phase of waste (i.e., solidified landfill after simple treatment), and there are very few up-to-standard treatment processes, technologies and devices involving the liquid phase (i.e. drilling wastewater). As of today, my country There is no treatment device that can make the drilling waste meet the overall standard, and there is no treatment device that can truly make all kinds of drilling wastewater treatment meet the first-level discharge standard of the "Integrated Wastewater Discharge Standard" (GB8978-1996)

The cost of foreign equipment is high, and the drilling fluid used is generally environmentally friendly, and the waste generated is not as complicated as that in China, which is not suitable for the actual situation of drilling operations in my country. Most oil fields have also spent huge sums of money to buy, basically It's a decoration

[0004] In addition, with the increasing difficulty of oil and natural gas drilling and development, the drilling depth increases, the composition of drilling fluid becomes more complex, and the disposal of the resulting waste becomes more and more difficult.

Previous processes, technologies and devices can no longer meet the current and future needs of drilling waste treatment and discharge

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