Preventing and mitigating corrosion problems can be very challenging due to technical considerations and prohibitive economic implications. It is thus imperative to arrest the escalating corrosion rates and impede the deterioration effects of corrosion with versatile remedies. In this review, previous research efforts on the application of plant-derived polysaccharides as potential inhibitors of metal corrosion in various aggressive media are studied. The deployment of corrosion inhibitors has proven to be an outstanding solution to prolonging the lifespan of metals. However, the most applied inhibitors such as the inorganic and some organic compounds are prohibitively expensive, hazardous, and toxic. These limiting factors have stimulated interest in more research into greener and less toxic natural alternatives. Considering the success of synthetic polymers for corrosion inhibition, a wide range of plants with high natural polysaccharide content have been evaluated to determine their effectiveness as biodegradable, renewable, and more economical corrosion inhibitors. Studies generally show that natural polysaccharides exhibit over 90% efficiency for corrosion inhibition with appreciable adsorption on the metal surface. Modification and grafting of the plant polysaccharides to enhance their inhibition efficiencies and to make them more desirable are currently being investigated. Such bio-inspired polymeric molecules thus have invaluable significance as potential alternatives for the problematic corrosion inhibitors.

Flow equations are necessary for the estimation of flow rate in pipelines. Several flow equations exist and so do conventions for their application. Their range of applicability are delineated in literature such as D. W. Schroeder, Jr. and GL Noble Denton (2010). These works record the limited range of applicability of the Weymouth Equation compared to other existing flow equations. This failing of the Weymouth Equation is most prominent in large diameter pipelines. Fully turbulent flow predominates in large diameter pipelines like trunk lines and the use of Weymouth Equation for calculation of flow rate in such scenarios results in significant discrepancies. This work extends the range of applicability of the Weymouth to fully turbulent flow regimes in large diameter pipelines. In particular, the Weymouth friction factor is corrected by introducing a term accounting for internal pipe roughness. Friction factors for different flow scenarios were calculated and plotted against the Reynolds Number and the Flow Rate to reveal the transition to fully turbulent flow regime. Python programming language was used to compute a table of friction data using both the Colebrook-White Equation and the Weymouth Friction Factor equation. A correction factor was introduced into the Weymouth friction factor that takes into consideration the variation of pipe roughness. Further, the new friction factor relationship was used to modify the existing Weymouth equation. The Modified Weymouth Equation obtained predicted well for fully turbulent flow scenarios. Compared against the Weymouth Equation, it maintained an appreciable efficiency as pipe roughness was varied from standard values obtainable with new pipelines. This study achieved its set objectives of improving the efficiency of the Weymouth Equation for large diameter pipelines. It will find application in the accurate estimation of flow rate as technologies evolve for non-intrusive determination of internal pipe roughness.

Two producing reservoirs (H10 and E40) in Eni field Offshore Niger Delta were studied with intent to enhance their rate of recovery while mitigating water production. The material Balance software MBAL was used to estimate the Stock tank oil reserves and then compared to reserve estimates determined by both deterministic and stochastic techniques for improved validation. The MBAL model was also used to identify positions of fluid contacts and determine predominant drive mechanisms. These serve as guide in making informed decisions towards if and how best to economically produce remaining unproduced oil in place. Input parameters were average values derived from core and well logs analyses. History matching of historical data enabled forecasts of possible future production life and volume at multiple scenarios. Final outcomes show that after sixteen and forty five years of continuous  production from the reservoirs studied (H10 and E40, respectively), remaining unproduced oil in place are still significant and can be economically produced by infill wells, which will in return increase the average production by nothing less than 33% of remaining oil in place, a substantial value bearing in mind the growing demand for oil, gas  and other energy sources to lessen the apparently unquenchable world energy needs.

This paper highlights efforts to eliminate wax production, by deriving a permanent flow assurance solution for a producing well and mitigate frequent downtime and expensive remediation operation. In two case studies, the efficacy of a Paraffin dispersant was compared with that of a Paraffin inhibitor, with respect to a producing well's wax formation tendencies and characteristics with the view of optimizing well performance subject to chemical injectivity. In the first case, well fluid was continuously treated with Paraffin dispersant to prevent wax deposition and subsequent blockage on the flowline but this effort proved ineffective because of periodic remediation. There was no significant performance improvement in this case. In the Paraffin inhibitor case, an appreciable increase in pressure differential across choke was observed as well as significant production increase which improved with the treatment time of the well fluid with the paraffin inhibitor. It was evident that Paraffin Inhibitor Injection was not just a flow assurance solution but also a production optimization tool. The project also saved the company about a million dollars annually, used for remediation of wax blockage on the flowline and sometimes sectional replacement of the flow line. Hence operation was a cost-effective method to achieve flow assurance and optimal production performance.

Introduction: Natural plant polymers demonstrate effective corrosion inhibition abilities, because of their numerous binding sites and excellent adsorption abilities.Methodology: In this study, the Box-Behnken method, gravimetric and electrochemical analyses were used to design and investigate the corrosion inhibition potential of a modified graft polymer of okra for mild steel in a 1M HCl medium. The influence of inhibitor concentration, temperature, and time were also investigated. Qualitatively, the Fourier Transform Infrared (FTIR) spectroscopy, Thermogravimetric Analysis (TGA), and Field emission scanning electron microscopy (FESEM) were used to characterize the extracts and evaluate the metal’s surface morphology.Results and discussion: The quantitative analyses showed that the modified natural polymer’s inhibition efficiency (IE) increased with concentration and reached 73.5% at 800 ppm, with a mixed-type mode of inhibition. From the response surface methodology, it was revealed that temperature influences the IE more than concentration and immersion time. The optimized IE using the desirability function showed the possibility of attaining 88.2% inhibition with inhibitor concentration at 142.3 ppm, temperature at 60.4°C, and an immersion time of 22.4 h. The new functional groups in the hybrid polymer revealed by FTIR analysis shows that grafting improved the inhibitor’s adsorption abilities. TGA analysis confirmed the extract’s high thermal stability, which highlights the inhibitor’s strong adsorption and efficiency for high temperatures. FESEM analysis indicated evidence of inhibitor adsorption onto the metal surface.Conclusion: These findings suggest that the grafting of okra with acrylamide enhances its inhibition properties and contributes to its functionality as a cost-effective plant-based alternative inhibitor against corrosion for mild steel facilities.

Accurate determination of molecular weight of heptane plus() fractions is essential in reliable phase behavior calculations and compositional EOS modeling studies. Empirical correlations provide cheaper alternatives in time and cost, to obtaining reliable molecular weight data than by experiments, though with compromised accuracies.Several empirical correlations developed to predict molecular weight of fractionsof petroleum were reviewed. A new correlation for calculating molecular weight of heptane plus fractions of light crudes was developed from a database compiled from Niger Delta fields for over 1,200 light crude oil assays, conventional PVT reports, and literature data. The correlation was developed using rational multiple regression analysis method.The new correlation's performance was compared with five others which do not depend on boiling point temperatures. Results showed that the new correlation has superior performance with the lowest absolute average and relative mean square errors. The new correlation had an average relative error of 8.15%, root mean square error of 0.09% and correlation coefficient of 0.955.

Plant extracts have been shown to effectively inhibit the corrosion of metals. Using the Box-Behnken, gravimetric, and electrochemical techniques, analyses were designed to investigate the anti-corrosion potential of okra in a 1M HCl medium. The inhibition performances derived from the various methods were in good agreement, demonstrating that physio-chemisorption was effective and adhered to the Langmuir isotherm. The efficiency of okra mucilage powder was 96% at a much lower concentration, compared to 91.2% and 88.4% for the unsieved extract and gelly-okra filtrate, respectively. FTIR results showed the presence of several functional groups that promoted adsorption, and TGA analysis revealed that the extract had high thermal stability. The FESEM analysis also revealed evidence of adsorption. It was determined that corrosion inhibition by okra mucilage extract was primarily influenced by temperature, followed by extract concentration, with immersion time having the least effect. From the model optimization goal, 200ppm, 60°C, and 24h for 89.98% IE gave a high desirability. The results showed the high capacity of okra as an efficient biodegradable corrosion inhibitor.

Oilfield scales are crystalline minerals made up of Na, K, Mg, Ca, Ba, Sr, Fe, Cl from produced water that can precipitate out in the reservoir, well, pipelines and process during the production and transportation of oil and gas. These precipitates can deposit as a result of thermodynamic and/or chemical changes and pose costly flow assurance issues to the oil industry. Several factors have been identified to be responsible including temperature, pressure, ionic strength, pH, evaporation, bicarbonate anion, super-saturation and contact time and water chemistry. Attempts to solve this problem in the past have focused mainly on the use of chemical inhibitors and the most accepted mechanism of scale inhibition is squeeze injection method. While adsorption and retention of scale inhibitors on rock formations needs more research, there had been improvement to better ways of ensuring adsorption and precipitation through nanotechnology including the use of nano-carbon enhanced squeeze treatment (NCEST). The uses of these conventional inhibitors have been found to be toxic to the flora and fauna in biotic communities during water disposal. In order to reduce the environmental burden caused by these conventional solutions and still manage the problem effectively, greener solutions have been proposed. This review x-rays the mechanisms of scale precipitation and deposition, evaluate the solutions that have been provided in literature based on efficiency, economics and environmental impact and propose guidelines to field operators in selecting optimum solutions.