Chemical Inhibitor Adsorption and Desorption Characteristics of Common Gravel Pack Sands Under Static and Dynamic Conditions

Abstract

In fields or wells with active programmes of scale and corrosion management via chemical inhibitor injection, the performance of the injected chemical inhibitor species in terms of their adsorption and desorption characteristics is very crucial to the success of the chemical injection programme. Benchmarks for measuring inhibitor performance include rapid, relatively steep adsorption isotherms and slow, relatively less steep desorption isotherms. The adsorption and desorption characteristics of three different pack sands taken as reservoir formation analogues were investigated using static and dynamic laboratory tests. Specifically the investigation focussed on petrophysical and grain parameters controls on adsorption and desorption characteristics of these sands. Correlation of adsorption intensity with sand uniformity coefficient exhibited a direct relationship for the static model whilst it exhibited an inverse relationship for the dynamic model. Contrastingly correlation of adsorption strength with uniformity coefficient exhibited 2 an inverse relationship for the static model and a direct relationship for the dynamic model. Integration of correlation coefficients from the adsorption/desorption data with adsorption intensity, adsorption strength and adsorption capacity showed that Freundlich model was better suited to modelling the adsorption/desorption characteristics of the gravel pack sands.

Effect of Produced Sand Particles and Fines on Scale Inhibitor: A Review

“…Oluyemi [16] reported that adsorption and desorption characteristic of formation in unconsolidated reservoir rocks may be affected by grain-size distribution, porosity and permeability, and eroding effects of particles of sand in motion. Oluyemi further ascertained that the eroding effects of sand particles can cause a reduction in the amount of inhibitors adsorbed as a result of reduction of the surface area of sand available for adsorption or the stripping off of the already adsorbed inhibitor species from the formation.…”

“…Nevertheless, scale inhibitors are one of the recent technologies used to mitigate waterinsoluble scale during oil and gas production [12][13][14][15][16][17]. Scale inhibitors are chemicals which delay, reduce, or prevent scale formation when added in small amounts to normally scaling water [9].…”

Effect of Produced Sand Particles and Fines on Scale Inhibitor: A Review

“…The physical size and form of the solid particles, the chemistry of the adsorbent, namely, degree of ionization at the surface, the types of functional groups present and the degree to which these properties change in contact with an aqueous solution are important considerations in determining the adsorption capacity of a solid (Gupta and Bhattacharyya, 2014). Oluyemi (2013) adsorption (Gupta and Bhattacharyya, 2011). Zhang and Somasundaran (2006) in their report claimed that there was a sharp increase in the adsorption of calcium on quartzitic surface and they attributed the increase to chemisorption caused by hydrolysed calcium ions.…”

“…The squeezing of scale inhibitor into formations to treat scale problems in order to sustain production at the right level has been a dominant practice in the oil and gas sector. Many researches have been carried out in this field (Jordan et al, 2016;Farooqui and Sorbie 2016;Stamatakis et al, 2006, Andrei andMalandrino 2003;Oluyemi 2013;Veloso et al, 2014).…”