Sharif Digital Repository

Acidizing of carbonate oil-wet rocks saturated with oil and saline formation water is subjected failure in some cases due to acid-induced damage such as sludge and emulsion formations. This condition may also lead to mineral precipitation, oil film barrier between acid and rock and diversion chemical malfunctions. Therefore, pre-flush process has been proposed as one of the most efficient stage for oil-wells matrix acidizing to reduce these challenges significantly. Besides, the pre-flush stage would result in more clean rock as the reservoir fluids are pushed back from the near wellbore regions, restoring rock wettability to more water wet state, preventing direct acid-oil contact and... 

Sweeping gas membrane distillation process was studied using flat sheet hydrophobic PTFE membrane. The effects of operating parameters, including feed temperature, feed flow rate, sweeping gas flow rate, and feed concentration on the permeate flux, were determined. The feed temperature significantly influenced the permeate flux. Increasing the feed temperature increased the permeate flux. The increase of feed concentration caused to reduce the permeate flux due to the increase of concentration polarization effect and reduction of vapor pressure difference. Sweeping gas flow rate led to increase the permeate flux due to reduction of vapor pressure in the permeate side. Higher air flow rate... 

In this work, desalination of saline brines using the sweeping gas membrane distillation (SGMD) process is investigated. The Taguchi method was applied for optimization of the operating parameters. An L9 orthogonal array was used to investigate the influence of pertinent variables, including feed temperature (Tf: 45°C, 55°C and 65°C), feed flow rate (Qf: 200, 400 and 600 mL/min), feed concentration (Cf: 10, 25 and 50 g/L) and sweeping gas flow rate (Qc: 4, 10, and 16 SCFH) on the distillate flux. Results of the experiments showed that maximum distillate flux, which was about 10 L/m2 h, obtained at 65°C feed temperature, 16 SCFH sweeping gas flow rate and brackish water with 10 g/L salt... 

Acidizing is widely used to remove near-wellbore damage and enhance the inflow performance of the reservoir to boost the well oil production rate. However, when the injected acid exposes to reservoir oil, either asphaltic sludge or emulsion forms as acid-induced damages. Therefore, laboratory compatibility tests are required before every acidizing job to determine both the acid sensitivity of oil samples and the optimal dosage of chemical inhibitors that should be used to prevent sludge and emulsion formation. The lack of knowledge to predict the risk of asphaltic sludge and emulsion damages for different oil and acid systems necessitates expensive and time-consuming compatibility tests...