Study of barium sulfate dissolution by scale dissolver based on solutions of DTPA

Abstract

In offshore oil wells it is very common to perform seawater injection through injection wells for hydrocarbon recovery. When seawater, rich in sulfate ion, mixes with formation water, whose composition can contain divalent cations such as barium and calcium, it often leads to sulfate salts formation due to their chemical incompatibility. These salts can cause serious damage in production wells. The barium sulfate (BaSO 4) is the most problematic scale and may cause many complications. In order to solve this issue, polycarboxylic acids, such as diethylene triamine pentaacetic acid, are used. Thus, the primary focus of this work was to develop an experimental procedure to study the BaSO 4 dissolution. Initially, through static tests to understand the relationship between dissolver concentration, temperature and dissolution time, and then through dynamic tests in sandstone reservoirs. Based on the results obtained, in the static tests the best condition for barite to dissolve was at high temperatures (80 ºC) and contact time of 48 hours, since from 50 °C there is an increase in dissolution rate, associated with a long contact time between dissolver and barite. In the dynamic tests, after scale formation, barite could be removed, but the high DTPA concentration should be avoided.

Environmental Performance of Alternative Green Polyol Synthesis Routes: A Proposal for Improvement

“…Barium (Ba) emissions to water and cypermethrin to soil are responsible for almost all the freshwater ecotoxicity impacts caused by R1. Barium salts are formed due to the reinjection of sea water in offshore wells, the main fossil energy resource sources in Brazil, and continue with oil and natural gas transport to refining units, where they must be removed so as not to affect process efficiency nor compromise equipment integrity [60]. When dispersed in the environment in its ionized form (Ba 2+ ), this metal becomes an important impact path for FWET.…”

Scale inhibitor qualification: evaluation for treatment in Brazilian pre-salt fields

“…On the other hand, sulfate scale is present whenever there is a mixture of incompatible waters -waters that can chemically react with each other. This mixture occurs, for example, when injection of sea water is used in production wells on offshore elds (Abib et al 2018). Considering the severity of Pre-Salt elds conditions, to prevent problems related to scale formation, an ideal inhibitor needs to have broad capacity to prevent several scales, tolerance to high salinity brines, temperature resistance and suitable pH range of action (Bai and Bai 2019).…”

The Simulation of Intermolecular Interactions of Carboxylic and Amine Groups With Calcium Carbonate

“…DTPA was formulated in the addition of oxalic acid, tannic acid, non-ionic surfactant, and water as a dissolver for real barium scale sample demonstrated efficiency of 71-77% at 35°C and 78-91% at 90°C dissolution efficiency, respectively [8]. A study highlighted the best condition for the BaSO4 scale to dissolve was at 80°C and a longer contact time of 48 hours to prolong the dissolution time of the solid scale [9]. 20 wt.% of DTPA and 6 wt.% potassium carbonates, K2CO3 are exposed to both CaCO3 and BaSO4 scales.…”