Barium Sulfate Scale Removal at Low-Temperature

Abstract

Precipitation of the scale in the oil and gas reservoirs, surface and subsurface equipment, and processing and production facilities is a big problem as it affects petroleum production. The scale precipitations decrease the oil and gas production and cause economical loss. Solving this issue requires an engineering investigation to provide a safe, efficient, and economic solution. Consequently, this study proposed a developed dissolver for barium sulfate scales, where two field-scale samples were collected from different locations. The compositional analysis for scale samples showed that sample 1 is 100% barium sulfate where sample 2 has 97.75% barium sulfate and 2.25% of quartz. The composition of the developed dissolver has diethylenetriamine pentaacetic acid (DTPA) as a chelating agent, oxalic acid, and tannic acids as an activator, nonionic surfactant, and water as the base fluid. The new dissolver was investigated with extensive lab tests to determine the dissolution efficiency, precipitation tendency for the dissolved scale solids, corrosion rate, and fluid-rock interaction. The obtained successful results indicated that the developed dissolver had a dissolution efficiency for two real barium scale samples as the results showed 76.9 and 71.2% at 35°C and 91.3 and 78.4% at 90°C for samples 1 and 2, respectively. The new solution has a great performance compared with common scale dissolvers in the oil field as hydrochloric acid, ethylenediaminetetraacetic acid, and diethylenetriamine pentaacetic acid. The developed dissolver showed a very low precipitation tendency for the scale dissolved solids (1.9 and 3.2% for samples 1 and 2, respectively) under 35°C for 24 hours. Without any additives of corrosion inhibitors, the corrosion rate was 0.001835 g/cm2 at 6.9 MPa and 100°C for 6 hours. Injecting the developed dissolver for damaged sandstone core sample with barite mud by flooding test showed a return permeability of 115%.

Metagenomic Investigation of a Low Diversity, High Salinity Offshore Oil Reservoir

“…Barium, calcium, magnesium and strontium were also reported at higher concentrations than other metals in the samples at 594 mg/L (4.33 mM), 5434 mg/L (135.60 mM), 2005 mg/L (82.51 mM) and 633 mg/L (7.22 mM), respectively. These high metal concentrations remain within the range reported in other oil reservoir formation waters [39][40][41].…”

Pathways from Climate Change to Conflict in U.S. Central Command

“…We hypothesize that the time between militarized disputes is shortened when pairs of states experience rapid-onset disasters. 113 Hypothesis 7c: The climate change-related search for energy independence leads to the proliferation of civil nuclear programs and the increased risk of nuclear incidents that inadvertently escalate to interstate war.…”

Effect of Sulfate-Based Scales on Calcite Mineral Surface Chemistry: Insights from Zeta-Potential Experiments and Their Implications on Wettability

“…Generally, pH-dependent scales are easier to treat than pH-independent scales. , This is because pH-dependent scales can be easily treated by acid injection, while this is not suitable for pH-independent scales . Thus, it is better to inhibit their occurrence, which can be achieved using chemical inhibitors such as chelating agents, ,, regulation of thermodynamic conditions of temperature and pressure, or by proper formulation of injected brine. , …”

“…Studies have shown that sulfate scales can alter the surface properties and wetting behavior of rock surfaces. ,, Although an extensive body of literature is available for bulk precipitation reactions, , only a limited number of published articles ,− focus on the effect of scales on rock surface chemistry which greatly influences its wetting behavior. Nikoo and Malayeri examined sulfate scale/brine/rock interfacial interactions and the rock wettability due to CaSO 4 crystals.…”