Removal and Inhibition of Calcium Sulfate Scale in Waterflood Projects

1968 ◽  
Vol 20 (11) ◽  
pp. 1249-1256 ◽  
Author(s):  
C.F. Smith ◽  
T.J. Nolan ◽  
P.L. Crenshaw
2019 ◽  
Author(s):  
Ahmed Farid Ibrahim ◽  
Hisham Nasr-El-Din ◽  
Mohamed Abd El-baqi ◽  
Ahmed Abdelhay ◽  
Hossam Farouk ◽  
...  

2009 ◽  
Vol 62 (8) ◽  
pp. 927 ◽  
Author(s):  
Tung A. Hoang ◽  
H. Ming Ang ◽  
Andrew L. Rohl

A comprehensive study of the effects of nine organic additives on the formation of calcium sulfate scale in a pipe system was conducted using a multiple pipe flow system. Several factors that influence the inhibitory capability of phosphonic and carboxylic additives such as their chemical structure, their concentration, and the run time were closely scrutinized. Results showed that the organic additives influence the deposition of calcium sulfate on the walls of a pipe flow system at various levels. The superiority of the phosphonic additives, especially N,N,N′,N′-ethylenediaminetetramethylenephosphonic acid (EDTP) and nitrilotrimethylenephosphonic acid (NTMP), to other organic compounds with respect to scale prevention is discussed thoroughly. For the first time, it was demonstrated that a solution with a given concentration of inhibitor that is continuously refreshed in a pipe reactor becomes less effective over time. The morphology of the scales formed in the presence of different additives is also studied, using scanning electron microscopy.


Desalination ◽  
2021 ◽  
Vol 497 ◽  
pp. 114736
Author(s):  
Danielle J. Park ◽  
Omkar D. Supekar ◽  
Alan R. Greenberg ◽  
Juliet T. Gopinath ◽  
Victor M. Bright

CORROSION ◽  
1979 ◽  
Vol 35 (7) ◽  
pp. 304-308 ◽  
Author(s):  
GEORGE H. NANCOLLAS ◽  
WESLEY WHITE ◽  
FELIX TSAI ◽  
LARRY MAS LOW

Abstract A seeded growth method has been used to study the kinetics of crystallization of calcium sulfate dihydrate at various temperatures and at ionic strengths up to 0.6M. Under all conditions, the rate of reaction is proportional to the square of the relative supersaturation and is controlled by a surface process. The same kinetics are applicable for the growth of calcium sulfate hemihydrate at temperatures above 110 C. The organic phosphonates effectively retard scale formation, and diethylenetriaminepenta (methylenephosphonic acid), when present at a concentration as low as 10−7M, completely inhibits the growth of calicum sulfate hemihydrate at 120 C. By assuming that the inhibitor molecules are adsorbed on growth sites on the surface of the crystals, the inhibition can be interpreted in terms of a simple Langmuir adsorption isotherm.


Desalination ◽  
2012 ◽  
Vol 305 ◽  
pp. 31-37 ◽  
Author(s):  
Kalpana Chauhan ◽  
Rajeev Kumar ◽  
Muneesh Kumar ◽  
Praveen Sharma ◽  
Ghanshyam S. Chauhan

2012 ◽  
Vol 66 (1) ◽  
pp. 193-200 ◽  
Author(s):  
Xiaoxu Xue ◽  
Change Fu ◽  
Na Li ◽  
Fangfang Zheng ◽  
Weiben Yang ◽  
...  

The aim of this study is to report on the performance of a novel non-phosphorus antiscalant, acrylic acid (AA)-allylpolyethoxy carboxylate (APEC), being developed for calcium-sulfate scale inhibition in industrial water systems. The performance of AA-APEC on calcium-sulfate scale inhibition was compared with that of the two commercial inhibitors, polyamino polyether methylene phosphonates (PAPEMP) and polyacrylic acid (PAA), containing the same polyethylene glycol segments or carboxyl functional groups as AA-APEC. The study indicated that AA-APEC could act as a highly effective calcium sulfate inhibitor, having strong ability to inhibit the precipitation of calcium sulfate at a dosage of 2 mg L−1, showing approximately 83.6% inhibition. The results also showed that AA-APEC dosage, the solution pH, inhibiting temperature, concentration of Ca2+, and SO42− all play important roles in inhibiting calcium-sulfate precipitation. The precipitation thermodynamics and kinetics at different temperatures were also discussed. X-ray diffractometer (XRD) and scanning electron microscope (SEM) analysis showed that AA-APEC strongly affected the texture and the morphology of the deposited calcium sulfate. Calcium sulfate has been inhibited through stabilization by adsorption onto crystal growth sites of nascent crystals altering their morphology.


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