Process Characteristics of Water-based Self-curing Coatings for Sand Casting

Abstract The rheological and gas evolution characteristics of water-based self-curing coatings for sand casting were analyzed and the influence of coating-thickness and graded coating on self-curing rate of coatings was studied. It can be seen from the test results that: the new water-based self-curing coating has both the characteristics of thixotropic fluid and pseudoplastic fluid, which has moderate thixotropy rate and high brushing index, good brushability and excellent comprehensive balance of flow-levelling and anti-flowability. It can meet the rheological requirements of various coating methods. The self-curing speed of water-based self-curing coating increases in an approximately linear manner with the decrease of its thickness. Thick coating should be best to paint at one time in the premise of ensuring its surface quality. Although the gas evolution volume of the new water-based self-curing coating is approximately equal to that of ordinary water-based baking coatings, but the gas evolution speed of self-curing coatings is almost half as that of the latter, which provides good conditions for preventing gas hole defect of casting.

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SHALE GAS EVOLUTION IN CANISTER: EVOLUTION CHARACTERISTICS, CONTROLLING FACTORS AND IMPLICATIONS FOR EVOLVED GAS OCCURRENCE STATE

10.1130/abs/2019am-340992 ◽

2019 ◽

Author(s):

Wei Dang ◽

◽

Jinchuan Zhang ◽

Fengqin Wang ◽

Xuan Tang

Keyword(s):

Shale Gas ◽

Controlling Factors ◽

Gas Evolution ◽

Evolved Gas ◽

Evolution Characteristics ◽

Gas Occurrence ◽

Occurrence State

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Enhancement lubricity properties of water-based mud with nanoparticles

Azerbaijan Oil Industry ◽

10.37474/0365-8554/2020-10-70-74 ◽

2020 ◽

pp. 70-74

Author(s):

V.V. Guliyev ◽

◽

Keyword(s):

Yield Point ◽

Coefficient Of Friction ◽

Drilling Fluid ◽

Research Work ◽

Shear Thinning ◽

Rheological Parameters ◽

Drilling Process ◽

Drilling Mud ◽

Pseudoplastic Fluid ◽

Water Based

Currently, a great number of drilling fluids with different additives are used all over the world. Such additives are applied to control the properties of the drilling mud. The main purpose for controlling is to achieve more effective and safe drilling process. This research work aims to develop Water-Based Mud (WBM) with a Coefficient of Friction (CoF) as low as Oil-Based Mud (OBM) and better rheological properties. As it is known, produced CoF by WBM is higher than OBM, which means high friction between wellbore or casing and drill string. It was the reason for studying the effect of nanosilica on drilling fluid properties such as lubricity, rheological parameters and filtrate loss volume of drilling mud. The procedures were carried out following API RP 13B and API 13I standards. Five concentrations of nanosilica were selected to be tested. According to the results obtained, it was defined that adding nanosilica into the mud decreases CoF of basic WBM by 26 % and justifies nanosilica as a good lubricating agent for drilling fluid. The decreasing trend in coefficient of friction and plastic viscosity for nanosilica was obtained until the concentration of 0.1 %. This reduction is due to the shear thinning or pseudoplastic fluid behavior. After 0.1 %, an increase at PV value trend indicates that it does not follow shear thinning behavior and after reaching a certain amount of dissolved solids in the mud, it acts like normal drilling fluid. The yield point of the mud containing nanoparticles was higher than the basic one. Moreover, a growth in the concentration leads to an increase in yield point value. The improvement of this fluid system cleaning capacity via hydraulics modification and wellhole stability by filter cake endurance increase by adding nanosilica is shown as well. The average well construction data of “Neft Dashlary” field was used for the simulation studies conducted for the investigation of hydraulics parameters of reviewed fluids for all series of experiments. The test results were accepted reliable in case of at least 3 times repeatability.

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