Metallurgical Design of Newly Developed Material for Seamless Pipes of X80–X100 Grades

With the increasing development of oil and gas fields in deepwater or ultra-deepwater with deep well depth, the development of high strength seamless pipe has become necessary. This paper describes a metallurgical design of seamless pipe with high strength reaching X80–X100 grade (minimum yield strength, 552 MPa–689 MPa) manufactured by steel containing very low carbon and with a microstructure of uniform bainite. The effect of microstructure of quenched and tempered (QT) steel on strength and toughness is investigated in laboratory. Uniform bainitic structure without coarse martensite-austenite constituent (M-A) is obtained by lowering bainite transformation temperature during quenching process by controlling the alloying elements. Moreover the structure is very effective in obtaining good toughness for tempered steel even with the high strength X100 grade. Sufficiently low hardness and good toughness in heat affected zone (HAZ) are confirmed by welding tests. The trial production of developed steel is conducted by applying inline QT process in medium-size seamless mill according to an alloying design obtained in laboratory tests. The seamless pipes of the trial production achieve grades X80 to X100 by changing tempering temperature. Some data of mechanical properties of the produced pipes is introduced.

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Challenges and their remedies while cementing production casing in high-temperature wells

Oil and Gas Studies ◽

10.31660/0445-0108-2019-1-39-46 ◽

2019 ◽

pp. 39-46

Author(s):

Vasiliy P. Ovchinnikov ◽

Pavel V. Ovchinnikov ◽

Alexander V. Melekhov ◽

Oksana V. Rozhkova

Keyword(s):

Oil And Gas ◽

High Strength ◽

Oil Well ◽

Hydrocarbon Production ◽

New Methods ◽

Oil And Gas Fields ◽

Deep Wells ◽

Long Time ◽

Gas Fields ◽

Reliable Isolation

The development of the global oil industry is closely related to the exploration of new oil and gas fields through the drilling new deep and ultra-deep wells, as well as the application of modern methods of hydrocarbon production. Usage of new methods of production, increasing the depth of the wells, bottomhole temperatures and pressures sets strict requirements and restrictions for the applied plugging materials. Oil well cements must have a long time of thickening to successfully complete the cementing process, grouting stone must have high strength characteristics, heat-resistant properties at high temperatures and provide reliable isolation of the annulus, also have corrosion resistance, ensure durability of the well lining.

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Failure Mechanism of Ultra-High Pressure Fluid Control Products

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.703.381 ◽

2014 ◽

Vol 703 ◽

pp. 381-384

Author(s):

Xin Long Chen

Keyword(s):

Electron Microscopy ◽

Impact Toughness ◽

Failure Mechanism ◽

Oil And Gas ◽

Surface Hardness ◽

Tempering Temperature ◽

Inclusion Content ◽

Ultra High Pressure ◽

Oil And Gas Fields ◽

Gas Fields

The square elbows used in oil and gas fields were often failed because of serious erosion. Some of the products even burst. In this paper, the failure mechanism of square elbow was investigated by using electron microscopy (OM), electron microscopy (SEM) methods. The research results show that the elbow products failed due to its low impact toughness after carburizing and quenching. The erosion angle is nearly ninety-degree. By increasing the tempering temperature, reducing the surface hardness and improving toughness, the serious erosion phenomenon can be effectively avoided. There are two main reasons of the elbow products burst. One reason is the high inclusion content of the material. The other is the low impact toughness. Raising the quality specification of materials can appropriate increase the low impact toughness after heat treatment. It is pointed out that the product would be more safety by improve its impact toughness.

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A Simple and Effective Method to Predict the Generation of Black Carbon in Oilfields

Volume 11: Petroleum Technology ◽

10.1115/omae2020-18432 ◽

2020 ◽

Author(s):

Guohua Dai ◽

Yufei Wan ◽

Chunyu Liu ◽

Jun Sang ◽

Wenguang Wang ◽

...

Keyword(s):

Black Carbon ◽

Oil And Gas ◽

Combustion Model ◽

Bohai Bay ◽

Test Results ◽

Low Carbon ◽

Fuel Gas ◽

Associated Gas ◽

Oil And Gas Fields ◽

Gas Fields

Abstract As an important safety discharge facility in petrochemical industry, flare is widely used in offshore and onshore oil and gas fields to relieve pressure, vent unwanted gases. This open-air combustion system oxidizes the fuel gases into carbon dioxide and water vapor and hence avoids the contamination of air with harmful gases that cause air pollution and climate change. With the increasingly strict requirements of environmental protection and the implementation of low-carbon development policy, the black carbon (soot) caused by incomplete combustion from the flare will be strictly controlled. At present, there is no simple and effective method to determine whether the flare produces visible black carbon which exacerbates the pollution. According to the investigation on site, there are different degrees of black carbon emission from the flares both in the onshore and offshore oilfield, which brings some troubles to the petroleum corporation. Based on a flare tip and the associated gas from an oilfield in Bohai Bay of China, a simulation model, which in accordance with the actual situation, was established with the Computational Fluid Dynamics software. The Non-Premixed Combustion model was used to simulate the Combustion, the P-1 model was adopted to calculate the thermal radiation and the Moss-Brookes model was selected to compute the generation of black carbon. The feasibility of the model was demonstrated by comparing the simulation results with the field test results. Then the limitation of current conventional practice to predict whether the soot is produced, was demonstrated with the model. At the same time, the production rate of black carbon under different conditions of components and fraction were calculated. After a comprehensive analysis and comparison, a simple, directly and effective method to predict the soot was proposed. When the C-to-H ratio of fuel gas is greater than 0.273, it tends to visible soot, and when the C-to-H ratio is greater than 0.285, it tends to heavy soot, which is in line with the actual in site. Therefore, the method can be applied to predict the level of the generation of black carbon in the engineering.

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