Changqing Oil Drilling Cuttings Treatment Case

After drilling and completion of more than 20 oil Wells in Longdong main oil area of Changqing Oilfield, more than 8,000 tons of downhole cuttings generated from the production site were transported to the local Qingcheng brick making enterprise for secondary utilization to make sintered bricks, thus solving the problem of comprehensive treatment of drilling waste in oilfield development and realizing the safe and environmental protection resource utilization of water-based cuttings. This is only a microcosm of the industrial reapplication of oil and gas drilling cuttings to save energy and reduce consumption.

Effective utilization of solid waste resources is the best way to dispose drilling cuttings. In the early stage, since the “collection while drilling” treatment of drilling waste in Changqing Oilfield, the cost of outsourcing drilling cuttings is high, and the disposal occupies a lot of land, and there is a large safety and environmental protection risk. The relevant technicians selected nearly 100 oil and gas Wells in the whole oil and gas field according to different regions, formations and drilling fluid systems for sampling while drilling, and the test results all showed that water-based drilling cuttings were general industrial solid wastes. Researchers have carried out detailed analysis and testing of drilling cuttings, and innovated a variety of resource utilization ways such as paving of cuttings, paving well sites and making brick from cuttings, and improved the geotechnical properties of drilling cuttings, forming the drilling cuttings adding a certain proportion of lime and fly ash, which can meet the requirements of paving well sites and roadbed. By analyzing the characteristics of the cuttings, the additive formula of the cuttings free brick is overcome, which is based on ordinary Portland cement and supplemented by water-based epoxy resin. At the same time, the firing process of the cuttings, clay and coal gangue of the sintered brick is studied.

Changqing Oilfield has made a breakthrough in the non-landing disposal technology of rock cuttings to make the drilling site clean. The treatment process of “miscible collection + rubber breaking and destability + plate and frame press filtration” was established to achieve the maximum solid-liquid separation and the solid water content was less than 75%. To solve the problem of low pressure filtrate recovery rate after plate and frame filtration, in order to recycle liquid phase between Wells or well sites, an integrated treatment agent with a variety of mixtures was developed. The liquid phase recovery rate was greater than 65%, meeting the Class I industrial solid waste, solving the contradiction between mud non-landing process and drilling production, and fully realizing the transformation and upgrading from “in-situ curing” to “clean” treatment.

At present, the disposal and resource utilization technology of drilling cuttings in Changqing Oilfield has reached the industry standard in terms of pollution control, process design and operation management involved in the resource process of water-based drilling cuttings and liquid phase, and has realized the full coverage of safe and environmental protection disposal of drilling mud in Sulige, Yulin, Yan ‘an and other places in Changqing oil and gas area. It has obtained 5 invention patents, introduced 3 Changqing oilfield standards and 1 industry standard, further standardized the resource utilization of solid waste in oil and gas fields, reduced regional environmental risks, and turned waste into treasure after millions of square drilling cuttings and oily sludge treatment in oil fields.

KOSUN- China Solids Control Leader&Drilling Waste Management Expert
WhatsApp/Wechat:+86 13379250593
Contact person: Monica Li
Online consulting:

What are the drilling methods?

  1. Jet drilling
    The high-pressure mud transported by the mud pump forms a high-speed impact jet (usually above m/s) through the drill bit nozzle, which directly acts on the bottom of the well, making full use of hydraulic energy (generally more than 50% of the pump water power acts on the bottom of the well), so that The cuttings are washed away from the bottom of the well in time or the formation is directly broken, which can greatly increase the drilling speed. A reasonable way to work is to use higher pump pressure, lower displacement and smaller drill nozzle diameter. Optimized parameter drilling is based on the analysis of drilling data, using electronic computers as a means, and using optimization methods to combine various controllable factors that affect the drilling speed (such as drill bit type, bit weight, rotation speed, mud performance, hydraulic factors, etc. ), establish a mathematical model and compile a calculation program based on the lowest cost principle. Optimal cooperation is carried out to achieve high-quality, fast and low-cost drilling work.
  2. Formation pore pressure prediction and balanced pressure drilling
    Use seismic, logging and drilling data (mechanical penetration rate, shale density, mud gravity, temperature, etc.) to conduct comprehensive analysis to predict formation pore pressure and determine possible abnormal pressure formations, and take timely measures to prevent sudden occurrences Complex underground situations such as blowout, lost circulation and well collapse. Based on the known formation pore pressure and formation fracture pressure, determine reasonable mud specific gravity and casing procedures. Drilling under conditions where the mud column pressure and formation pore pressure in the well are approximately balanced is called balanced pressure drilling. It can significantly increase the drilling rate and is also beneficial to the discovery of oil and gas reservoirs. Well control technology: When drilling into abnormally high-pressure formations and mud gas invasion or well kick occurs, calculation methods and appropriate technical measures are used to adjust the mud proportion and flow characteristics, and use hydraulic high-pressure blowout prevention equipment to control and eliminate well overflow. , to prevent blowouts.
  3. Core taking technology
    According to the design requirements, rock samples (cores) of the required layers are drilled from underground to obtain primary data for the exploration and development of oil and gas reservoirs. Commonly used coring tools are mainly composed of core drill bits, core barrels, core grabs, joints and other components. During coring drilling, the drill bit continuously cuts the rock at the bottom of the well in an annular shape, so that the drilled columnar core continuously enters the core barrel. In order to meet special needs, there are also closed coring, pressure maintaining coring and coring tools (rubber sleeve coring tools) for extremely loose and broken formations.

The vacuum degasser is a new type of special equipment used to deal with gas intrusion into drilling mud

The vacuum degasser is a new type of special equipment used to deal with gas intrusion into drilling mud. During the drilling process, it plays an important role in restoring mud specific gravity and stabilizing mud performance. This innovative technology revolutionizes the way gas intrusion drilling mud is managed, providing the oil and gas industry with a more efficient and effective solution.

Gas intrusion in drilling mud can cause various problems such as reduced drilling efficiency, formation damage, and wellbore instability. Vacuum degasser solves these challenges by removing entrained gases such as methane, carbon dioxide and hydrogen sulfide from drilling fluids. This process helps maintain the integrity of the mud, ensuring it can effectively carry cuttings to the surface and provide adequate support for the wellbore.

The working principle of the vacuum degasser is to create a low-pressure environment in the container to separate the gas from the mud. This is accomplished through the use of a vacuum pump, which draws the gas-laden slurry into a degassing unit. Once inside, the slurry is agitated to release the entrained gas, which is then expelled from the system. The degassed mud is then returned to the mud circulation system, ready to continue its role in the drilling process.

One of the main benefits of using a vacuum degasser is its ability to improve the overall performance of the drilling mud. By removing entrained gas, the mud’s specific gravity is restored, ensuring it can effectively suspend and transport cuttings. This helps maintain wellbore stability and prevent problems such as kicks and blowouts. In addition, the removal of gas enhances the rheological properties of the mud, ensuring that it maintains its desired properties throughout the drilling operation.

Overall, vacuum degassers have become an indispensable tool in the oil and gas industry, providing a reliable and efficient means of managing gas intrusion into drilling muds. Its ability to restore mud gravity and stabilize mud properties makes it a valuable asset in ensuring a successful drilling operation. As technology continues to advance, vacuum degasser will play an increasingly important role in optimizing drilling processes and improving overall operational efficiency.

Sand pumps are important equipment used to transport slurry in various industrial applications

Sand pumps are important equipment used to transport slurry in various industrial applications. It plays a vital role in the efficient movement of mud, making it an indispensable tool in the drilling and mining industry. Sand pumps are designed with a range of features that make them functional and efficient.

One of the key components of the sand pump is the impeller, which adopts a closed design to ensure high transmission efficiency. This design allows for seamless movement of slurry, allowing the pump to handle large volumes of material with ease. The efficient operation of the impeller helps improve the overall performance of the sand pump, making it a reliable choice for demanding applications.

In addition to the impeller, the sand pump is also equipped with a highly wear-resistant carbide mechanical seal. The seal is designed to withstand the wear and tear of mud, ensuring a long service life for the pump. The wear-resistant properties of the seals make sand pumps suitable for continuous operation in challenging environments, providing durability and reliability in slurry transfer.

In addition, the versatility of sand pumps is highlighted by their ability to serve as injection pumps or downhole supply pumps for drilling rig mud pumps. This flexibility allows the pump to adapt to different operating requirements, making it a versatile solution for a variety of slurry transfer needs. Whether used as an injection pump or downhole supply pump, sand pumps provide consistent performance and reliability when handling mud.

Overall, sand pumps are important equipment for efficiently transporting slurry in industrial environments. Its advanced features, including a closed impeller design, highly wear-resistant mechanical seal and versatility, make it a valuable asset in applications where reliable mud movement is essential. With high transfer efficiency and long service life, sand pumps are a reliable solution for transporting slurry in harsh industrial environments.