Corrosiveness or scaling is an inherent threat to oil operations. The primary cause for this threat is the presence of water having complex geochemical matrix. Unanticipated water production, particularly if it contai...Corrosiveness or scaling is an inherent threat to oil operations. The primary cause for this threat is the presence of water having complex geochemical matrix. Unanticipated water production, particularly if it contains unwanted impurities, can significantly impact hydrocarbon production. The current paper discusses the degree of threat posed to oil operation facilities based on the water characteristics. Methodology involved the collection and analysis of water samples from major sources in oil industry such as groundwater, wellheads and seawater. The parameters tested include geochemical, microbiological and pollutants. The lab data was used to develop scaling and corrosion prediction indices such as Langelier Saturation Index (LSI), Ryznar Stability Index (RSI) and Puckorius Scaling Index (PSI). The study indicated varying water chemistry for different sources. Mixing of those waters may lead to ionic saturation and scaling in different facilities. Presence of the SRB and GAB in some water sources also posed threat to water system by forming fouling and corrosion. Seawater used for offshore oilfields water injection to maintain reservoir pressure and improve oil recovery showed scaling tendency, whereas under different reservoir pressure, it can cause corrosion. Some of the samples also had corrosion residuals such as iron, which indicated active corrosion. Current study showed higher alkalinity with high sulfate for one groundwater sample with presence of active corrosion residuals such as dissolved iron and manganese. The study showed positive value for LSI which indicated supersaturation of the water samples with respect to calcium carbonate (CaCO<sub>3</sub>) and scale forming. Similarly, for RSI and PSI, the value was below six which confirmed the scaling potential for all the samples. Even though the index value was pointing towards scaling potential, the geochemistry, microbiology and presence of other impurities indicated corrosion threat to the oil and gas industrial facilities. The study concluded the importance of different scale inhibition mechanism and corrosion control in Oil and Gas industry.展开更多
Oil and gas industries generate a significant amount of water during the production. The composition of this water varies with the geologic age, depth, and geochemistry of the region along with the chemicals added dur...Oil and gas industries generate a significant amount of water during the production. The composition of this water varies with the geologic age, depth, and geochemistry of the region along with the chemicals added during the process. Geochemistry of formation water is used for aquifer identification, pollution problems, water compatibility studies, corrosion monitoring, water-quality control, water flooding, exploration, and to diagnose wellbore integrity issues. The current study investigates the spatial and temporal variation of produced water geochemistry from one of the largest conventional oil field, Ghawar field, Saudi Arabia. Produced water from different wellheads were collected and analyzed for different geochemical characteristics. Sixteen wells from ABQQ, nineteen wells from ANDR and twenty wells from SDGM area were selected for the current study. Sampling and analysis were performed as per the standard procedures. Results indicated that the pH of the sample varied from 6.0 to 7.4, and Electrical conductivity from 94200 to 102690 μS/cm. The spatial variation of major cations and anions were also recorded and represented by graphical plots. Metal analysis indicated the highest concentration for boron, which is 20.5 mg/L at ABQQ area, whereas all other metals are very low in concentration. Temporal variation of a single well at SDGM area indicated drastic change in the ionic concentration, whereas the geochemistry remains same as indicated by Tickler plot. The water type of the respective area was studied by tickler plots, which indicated same source of formation water in different wells at ABQQ, ANDR and SDGM areas. The ionic concentration is also used to predict corrosion and scaling issues. By Langelier Saturation Index (LSI) and Ryznar Stability Index (RSI), the sample from all the wells showed higher scaling potential. The study concludes that the water type in different areas under Ghawar field remains same regardless of drastic changes in the ionic concentration, which can be used to diagnose wellbore integrity issues.展开更多
文摘Corrosiveness or scaling is an inherent threat to oil operations. The primary cause for this threat is the presence of water having complex geochemical matrix. Unanticipated water production, particularly if it contains unwanted impurities, can significantly impact hydrocarbon production. The current paper discusses the degree of threat posed to oil operation facilities based on the water characteristics. Methodology involved the collection and analysis of water samples from major sources in oil industry such as groundwater, wellheads and seawater. The parameters tested include geochemical, microbiological and pollutants. The lab data was used to develop scaling and corrosion prediction indices such as Langelier Saturation Index (LSI), Ryznar Stability Index (RSI) and Puckorius Scaling Index (PSI). The study indicated varying water chemistry for different sources. Mixing of those waters may lead to ionic saturation and scaling in different facilities. Presence of the SRB and GAB in some water sources also posed threat to water system by forming fouling and corrosion. Seawater used for offshore oilfields water injection to maintain reservoir pressure and improve oil recovery showed scaling tendency, whereas under different reservoir pressure, it can cause corrosion. Some of the samples also had corrosion residuals such as iron, which indicated active corrosion. Current study showed higher alkalinity with high sulfate for one groundwater sample with presence of active corrosion residuals such as dissolved iron and manganese. The study showed positive value for LSI which indicated supersaturation of the water samples with respect to calcium carbonate (CaCO<sub>3</sub>) and scale forming. Similarly, for RSI and PSI, the value was below six which confirmed the scaling potential for all the samples. Even though the index value was pointing towards scaling potential, the geochemistry, microbiology and presence of other impurities indicated corrosion threat to the oil and gas industrial facilities. The study concluded the importance of different scale inhibition mechanism and corrosion control in Oil and Gas industry.
文摘Oil and gas industries generate a significant amount of water during the production. The composition of this water varies with the geologic age, depth, and geochemistry of the region along with the chemicals added during the process. Geochemistry of formation water is used for aquifer identification, pollution problems, water compatibility studies, corrosion monitoring, water-quality control, water flooding, exploration, and to diagnose wellbore integrity issues. The current study investigates the spatial and temporal variation of produced water geochemistry from one of the largest conventional oil field, Ghawar field, Saudi Arabia. Produced water from different wellheads were collected and analyzed for different geochemical characteristics. Sixteen wells from ABQQ, nineteen wells from ANDR and twenty wells from SDGM area were selected for the current study. Sampling and analysis were performed as per the standard procedures. Results indicated that the pH of the sample varied from 6.0 to 7.4, and Electrical conductivity from 94200 to 102690 μS/cm. The spatial variation of major cations and anions were also recorded and represented by graphical plots. Metal analysis indicated the highest concentration for boron, which is 20.5 mg/L at ABQQ area, whereas all other metals are very low in concentration. Temporal variation of a single well at SDGM area indicated drastic change in the ionic concentration, whereas the geochemistry remains same as indicated by Tickler plot. The water type of the respective area was studied by tickler plots, which indicated same source of formation water in different wells at ABQQ, ANDR and SDGM areas. The ionic concentration is also used to predict corrosion and scaling issues. By Langelier Saturation Index (LSI) and Ryznar Stability Index (RSI), the sample from all the wells showed higher scaling potential. The study concludes that the water type in different areas under Ghawar field remains same regardless of drastic changes in the ionic concentration, which can be used to diagnose wellbore integrity issues.
