Micromilling is a subtractive manufacturing process that presents challenges due to scale effects andrapid tool wear. To understand the evolution of surface quality when increasing the machined length during the micr...
详细信息
The Bongor is the main basin for increasing storage and production in the CNPC Chad. With the continuous deepening of development, underground safety operations face the following problems: the inability to effectivel...
详细信息
Energy types are constantly changing due to the change of demand, and natural gas as a clean energy is gradually accepted by the world at present. In order to ensure the stable supply of natural gas, long-term, safe a...
详细信息
The most fundamental purpose of reservoir stimulation is to maximize stimulation volume. Forreservoirs developed with natural fractures, the maximization of fracture activation (tensile & shear activation) area s...
详细信息
ISBN:
(纸本)9781613999813
The most fundamental purpose of reservoir stimulation is to maximize stimulation volume. Forreservoirs developed with natural fractures, the maximization of fracture activation (tensile & shear activation) area should be pursued. Many scholars have studied the mechanical conditions of natural fractures activation, and used stress shadow to optimize cluster spacing. However, there is a lack of in-depth research on fracture propagation law, relationship between fracture activation and stress shadow, and factors affecting natural fracture activation. In this paper, numerical simulation methods are used to establish a true three-dimensional hydraulic fracturing model forreservoirs with natural fractures, and the quantitative evaluation indicators of stress shadow area and activation degree of natural fractures are formed. By studying the effects of different natural fracture properties, mechanical and engineering parameters on fracture propagation, stress shadow and natural fracture activation, the main controlling factors affecting fracture propagation and turning, the relationship between fracture activation and stress shadow, and changing rules of fracture activation are clarified. Finally, the fracture turning and accuracy of model are verified by microseismic monitoring data. Studies have shown that large-scale, high-density natural fractures, high net pressure, low in-situ stress difference, and moderate stress-fracture angle (30°~60°) can easily divert the propagation of hydraulic fractures instead of expanding in the horizontal maximum principal stress (Shmax) direction. Fracture tensile activation has a strong positive correlation with stress shadow area, that is, tensile activation leads to the increase of stress shadow area, while fracture shear activation has almost no correlation. Fracture tensile & shear activation area is in a competitive relationship, and shear fractures are dominant when the stressfracture angle is 45-60°, the in-situ stress differenc
Challenges in drilling nickel-based superalloys, such as Inconel 718 (IN718), are multifaceted. High requirement of hole surface quality in drilling such alloy must deal with extreme material properties and complex pr...
详细信息
Challenges in drilling nickel-based superalloys, such as Inconel 718 (IN718), are multifaceted. High requirement of hole surface quality in drilling such alloy must deal with extreme material properties and complex process condition in drilling operation. This paper presents an experimental investigation on the effect of PVd coated solid carbide drills underdifferent internal cooling schemes on hole quality in drilling IN 718 alloy. Three types of solid carbide drills were used in the series of drilling experiments, including PVd coated and uncoateddrills, anddifferent design in the number of internal cooling channels, two channels and four channels. The objective of the investigation is to assess the effect of coating and efficiency of internal cooling on surface quality in drilling IN718 alloy. Surface quality on drilled holes in terms of roughness, burr formation, subsurface deformation and strain hardening has also been measured and analyzed on the machined specimen. The roughness and burr size on drilled holes demonstrated little differences among the three types of testing drills. Surface roughness was severely deteriorated by the chip trapped in the hole leaving scratch and smears on the surface. Nevertheless, the scheme of internal cooling channels and PVd coating exhibited noticeable influence on quality of drilled hole surface.
Oil-baseddrilling fluids possess excellent properties such as shale inhibition, cuttings suspension, and superior lubrication, making them essential in the development of unconventional oil and gas ***, wellbore inst...
详细信息
Oil-baseddrilling fluids possess excellent properties such as shale inhibition, cuttings suspension, and superior lubrication, making them essential in the development of unconventional oil and gas ***, wellbore instability, caused by the invasion of drilling fluids into shale formations, remains a significant challenge for the safe and efficient extraction of shale oil and gas. This work reports the preparation of mesoporous SiO2nanoparticles with low surface energy, utilized as multifunctional agents to enhance the performance of oil-baseddrilling fluids aimed at improving wellbore stability. The results indicate that the coating prepared from these nanoparticles exhibit excellent hydrophobicity and antifouling properties, increasing the water contact angle from 32°to 146°and oil contact angle from 24°to134.8°. Additionally, these nanoparticles exhibit exceptional chemical stability and thermal *** these nanoparticles into oil-baseddrilling fluids reduced the surface energy of the mud cake from 34.99 to 8.17 m J·m-2and increased the roughness of shale from 0.26 to 2.39 μm. These modifications rendered the mud cake and shale surfaces amphiphobic, effectively mitigating capillary infiltration anddelaying the long-term strength degradation of shale in oil-baseddrilling fluids. After 28days of immersion in oil-baseddrilling fluid, shale cores treated with MF-SiO2exhibited a 30.5% increase in compressive strength compared to untreated cores. Additionally, these nanoparticles demonstrated the ability to penetrate and seal rock pores, reducing the API filtration volume of the drilling fluid from11.2 to 7.6 m L. This study introduces a novel approach to enhance the development of shale gas and oil resources, offering a promising strategy for wellbore stabilization in oil-baseddrilling fluid systems.
Horizontal well technology is a favorable means for the efficient development of "deep, low permeability, offshore, unconventional" and other complex reservoirs, and its key is to improve the drilling rate o...
详细信息
The assessment of drilling crew is crucial for evaluating the operational effectiveness, improving management levels, and improving drilling operation quality and efficiency. Currently, most drilling crew operation ev...
详细信息
This paperdiscusses permanent deformation of the fuel assembly of pressurized waterreactors that have to satisfy a drop time requirement of the control rod assembly. during a seismic event, the fuel assemblies and t...
详细信息
during ultradeep oil and gas drilling,fluid loss reducers are highly important for water-baseddrilling fluids,while preparing high temperature-and salt-resistance fluid loss reducers with excellent rheology and filtr...
详细信息
during ultradeep oil and gas drilling,fluid loss reducers are highly important for water-baseddrilling fluids,while preparing high temperature-and salt-resistance fluid loss reducers with excellent rheology and filtration performance remains a ***,a micro-crosslinked amphoteric hydrophobic association copolymer(i.e.,dAdC)was synthesized using N,N-dimethyl acrylamide,diallyl dimethyl ammonium chloride,2-acrylamido-2-methylpropane sulfonic acid,hydrophobic monomer,and pentaerythritol triallyl ether *** to the synergistic effects of hydrogen bonds,electrostatic interaction,hydrophobic association,and micro-crosslinking,the dAdC copolymer exhibited outstanding temperature-and *** rheological experiments have shown that the dAdC copolymer had excellent sheardilution performance and a certain degree of salt-responsive viscosity-increasing *** dAdC copolymer could effectively adsorb on the surface of bentonite particles through electrostatic interaction and hydrogen bonds,which bring more negative charge to the bentonite,thus improving the hydration anddispersion of bentonite particles as well as the colloidal stability of the drilling ***,the drilling fluids constructed based on the dAdC copolymer exhibited satisfactory rheological and filtration properties(FLHTHP=12 m L)after aging at high temperatures(up to200℃)and high salinity(saturated salt)***,this work provided new insights into designing and fabricating high-performance drilling fluid treatment agents,demonstrating good potential applications in deep and ultradeep drilling engineering.
暂无评论