The Influence of Turbulence or Hydrodynamic Effects on Barium Sulphate Scale Formation and Inhibitor Performance

Abstract

Inorganic scale (carbonate, sulphate and sulphides) formation can be predicted from thermodynamic models and over recent years better kinetic data has improved the prediction of such scales in field conditions. However these models have not been able to predict the observed deposition where flow disturbances occur, such as at chokes, tubing joints, gas lift valves and safety valves. This can lead to unexpected failures of critical equipment such as downhole safety valves (DHSV's), and operational issues such as failure to access the well for coiled tubing operations due to tubing restrictions. In recent years it has been recognised that the turbulence found at these locations increases the likelihood of scale formation and experiments have been able to demonstrate that increased turbulence also impacts the minimum scale inhibitor concentration required to prevent scale. One of the industry standard test methods used to screen inhibitors for barium sulphate inhibition is the static bottle test. In this paper the ‘static’ bottle test method is modified to investigate the effects of increasing levels of turbulence on the formation of barium sulphate scale at two different temperatures and therefore different supersaturations for a fixed brine composition. Using this modified method it has been possible to demonstrate the impact of varying turbulence on the performance of two common generic types of scale inhibitor (phosphonate and vinyl sulphonate co-polymer). Data on the mass of scale formed, scale morphology using SEM imaging and inhibitor efficiency will be linked to degree of turbulence and scale inhibitor functionality (nucleation inhibition vs. crystal growth retardation). The findings from this study have significant impact on the methods of screening scale inhibitors for field application that should be utilised and development of suitable chemicals that perform better under higher shear conditions.

Inhibition of Barium Sulfat Crystal Formation in a Batch Method Crystallizer in the Presence of Cu and Zn

“…The barite crystals formed at higher rotational speeds (figure1 c) are more numerous and relatively thicker, implying that the stirring speed can affect the number of crystals formed. This result different with previous result which Turbulence or Hydrodynamic Effects on Barium Sulphate Scale Formation and Inhibitor Performance(15) The formation of barite on the solid substrate occurred as a two stages process, and the crystallization rate of barite may be controlled (or at least affected) by the presence of chemical scale inhibitors(16),(17).Analysis of X-Ray Diffraction (XRD)The crystal phase of barium sulfate was analyzed using an X-ray diffractogram to determine whether the crystal phase formed was truly barium sulfate (BaSO4) crystals or not.…”

Iron Sulfide Scale Inhibition in Carbonate Reservoirs

“… 21 , 22 However, some recent literature shows that such laboratory experiments underestimate the amount of scale that can potentially form in dynamic testing methods. 23 The dynamic tube-blocking tests work on tube blockage; they are often used to determine minimum inhibitor concentration. On the other hand, dynamic filter-blocking tests incorporate small-size filters to evaluate the adsorption of scale inhibitors.…”

“…Static bottle tests are used for screening the different types of inhibitors. , However, some recent literature shows that such laboratory experiments underestimate the amount of scale that can potentially form in dynamic testing methods . The dynamic tube-blocking tests work on tube blockage; they are often used to determine minimum inhibitor concentration.…”

High Return Performance of Calcium Phosphonate (Ca-DTPMP) Colloidal Inhibitors for Squeeze Treatment in Shale Formations

“…Scale formation has been a continuous challenge associated with the oil and gas industry. Scale formation can cause severe blockage problems in downhole equipment, wellbore, production tubulars, pump, separator, and so on, resulting in production decline, formation damage, increased cost, and even well shut-in (Guo et al, 2012;Sutherland et al, 2013;Veisi et al, 2018).…”