Drilling fluids and cuttings are emitted during drilling. According to the American Petroleum Institute estimates that only 1995, the United States onshore drilling to produce about 150 million bbl drilling waste, so the drilling waste recycling is urgent need nowadays.
In order to minimize drilling waste, the use of environmentally friendly tertiary waste treatment methods:
(1) adjust the drilling process or use the appropriate drilling fluid, so that the waste generated by the drilling process at least;
(2) will have been reduced to Minimum drilling waste is recycled as much as possible; and
(3) disposal of drilling waste that can not be recycled by lawful meant.
1. Use synthetic base drilling fluid
The new synthetic base drilling fluid has the drilling characteristics of oil-based mud, but does not contain polycyclic aromatic hydrocarbons, but also has low toxicity, faster biodegradability and low bioaccumulation. Will not bring great environmental impact to the seabed. Compared with water-based mud, synthetic mud makes the wellbore cleaner and more stable, resulting in fewer cuttings and can be recycled, usually water-based mud cuttings directly into the sea.
2.Drilling fluid recycling
Will be used oil-based mud and water-based mud recycling, to minimize the amount of drilling waste emissions.
3. Treatment of drilling waste
Conventional land-based drilling waste is treated by first extracting the liquid portion of the slurry pool and then landing or dispersing the remaining solid material in situ. In oil and gas production areas, oilfield waste is dedicated to landfills; other areas will meet the emission standards of drilling waste transported to urban or industrial waste landfill. Another approach is to recycle the waste into the formation through the drilling annulus, including pouring the effluent into the formation fractures at a pressure above the formation fracture pressure or pouring the effluent into the formation at a pressure below the formation fracture pressure Natural cracks and salt holes.
Oil and gas industry has made great progress in environmental protection, there are a variety of drilling waste disposal methods, operators can be in accordance with the relevant legal requirements, cost and environmental requirements to choose the most appropriate drilling dirt treatment methods. New drilling waste disposal methods are being studied to meet future environmental requirements.
Drilling waste disposal more and more get recognized and popoular in industry.
Over the past few decades, the oil and gas industry has taken various measures to minimize the waste generated by drilling in order to better protect the environment and public safety.
Drilling operators use environmentally friendly tertiary waste treatment methods to deal with drilling waste:
in the first stage, the operator adjusts the drilling process or displaces the appropriate drilling fluid to minimize the waste generated during the drilling process. This is both for the operator to reduce the cost of dirt treatment, but also more conducive to environmental protection.
The second stage, will have been reduced to a low limit of drilling waste as much as possible recycling.
The third level, through a legitimate way to deal with can not be recycled drilling waste.
Offshore drilling waste disposal is limited to emissions, re-injection or return to shore.
In contrast, land operators have a large range of options in dealing with drilling fluids.Usually onshore drilling waste in situ; on the offshore platform, most of the water-based mud and cuttings and synthetic slurry are poured into the sea; some land drilling waste is transported to commercial waste disposal outside the well siteAnd offshore oil-based mud and cuttings must be returned to shore or re-injected into the ground at the well site.
At present, drilling companies are studying new drilling fluids for different stratigraphic conditions.The new drilling fluid not only has the proper drilling characteristics, but also contains less harmful additives that inhibit vegetation growth.The use of new, more environmentally friendly additives in place of important components in drilling fluids, such as the use of ilmenite powder instead of barite powder as a mud aggravating agent, can reduce the impact on the environment. Current drilling fluid heat treatment costs are high, and not suitable for offshore use.The future may improve the drilling fluid heat recovery drilling waste treatment technology, reduce processing costs, improve the organic lye recovery rate.The new approach will improve safety and effectiveness and make it suitable for offshore drilling platforms.
Drilling Waste Treatment Equipment With the development of the oil industry, the pollution problems caused by drilling are also getting more and more attention. China’s oil field per year only drilling production of waste drilling fluid produced about more than 900,000 cubic meters, of which one-third of the discharge to the environment, the environment and stratigraphy have caused varying degrees of pollution. Drilling pollution is mainly based on waste drilling fluid and waste water pollution.
Drilling produces waste, including waste drilling fluids, diamond cuttings with drilling fluids, simply a mixture, such as excess cement, isolation fluids and other fluids. The amount of drilling waste is determined by a number of factors including the size of the wellbore, the efficiency of the solid-controlled equipment, the solid-phase capacity of the drilling fluid, the ability of the drilling fluid to inhibit the dispersion of the cuttings, and the amount of drilling fluid remaining on the cuttings. The percentage of solid phase in the waste drilling fluid varies from 50% to 25% of the maximum. There is always a certain amount of drilling fluid with the cuttings together with the waste, no matter how good the solid control equipment, drilling fluid can not be separated from the cuttings. If these effluents are discharged, they will cause significant pollution to the environment.
Abandoned drilling mud pollution of the environment, in essence, waste drilling mud in the liquid phase of the environment pollution, vertical cutting， liquid reuse as a resource recycling as an important means of waste disposal. In response to this issue, Tsunami Oil conducted a three-year repeated research and experiment, through a different treatment process, successively in Xinjiang Tarim Oilfield, Daqing Oilfield and other drilling waste disposal equipment on-site construction, Solid phase to meet the national requirements of the emission standards, most of the liquid phase as a slurry base for the re-use of resources, only a small amount of liquid after the depth of treatment after the standard discharge or re-injection. A large extent to reduce the production costs of drilling fluid, but also to achieve the energy-saving emission reduction, the purpose of safety and environmental protection.