Papers by Salihu Suleiman
American Academic Scientific Research Journal for Engineering, Technology, and Sciences, Feb 18, 2021
Despite the continued research effort on erosion behavior of multiple flat fan nozzles in removin... more Despite the continued research effort on erosion behavior of multiple flat fan nozzles in removing different types of scale deposits from petroleum production tubing, effect of chamber air concentration and nozzles configuration is yet to be given detailed consideration. This study, therefore, considers the utilization of multiple high-pressure sprays at different chamber air concentration to enhance the rate of scale removal from petroleum production tubing. Additionally, options of altering chamber air/water ratio and header configurations for more effective scale removal were explored. Also, the effect of nozzle header arrangements on the removal of paraffin of different stages of deposition in petroleum production tubing is investigated. The selection of chamber air concentration and header configuration (nozzles arrangement) for effective scale removal was found to be governed by the shape and type of the scale deposit. Furthermore, the descaling capacity increases with decrease in number of nozzles due to pressure drop effect irrespective of the type or shape of the scale deposit. This novel descaling experiment of utilizing 10MPa injection pressure from 25mm jetting position averagely removes hollow paraffin deposits that range from 44g to 280g and 34g to 89g of solid shaped paraffin as a result of altering nozzles configuration. Correspondingly, an average removal difference ranging from 48g to 270g of hollow shaped and 35g to 218g of solid shaped paraffin deposit was recorded as a result of compressing the chamber pressure by 0.2MPa and subsequently suctioning it by-0.008MPa respectively.
American Academic Scientific Research Journal for Engineering, Technology, and Sciences, Jun 13, 2021
Despite the continued research efforts in understanding the erosional behaviors of multiple flat ... more Despite the continued research efforts in understanding the erosional behaviors of multiple flat fan nozzles in the removal of different types of scale deposits from petroleum production tubing. The non-hydrodynamically connected descaling parameters such as stand-off distance, nozzle arrangement and chamber pressure have not been duly considered up to date. This research utilizes 3-flat fan high-pressure nozzles at a high injection pressure of 10 MPa to remove paraffin deposits at different growth stages from petroleum production tubing to evaluate the effects of the descaling parameters on scale removal. A stand-off distance of 25 mm, 50 mm and 75 mm; nozzle arrangement in novel orientations (triangle, diagonal & right-angle) involving 7-nozzles header and chamber pressures (in compression-0.2 MPa and vacuum-8.0 x10-3 MPa) were utilized as the varying nonhydrodynamically connected parameters. Generally, the selection of both nozzle arrangement and chamber air concentration was found to be governed by the type and shape of the deposit in question while the scale removal capability was found to be reduced with an increase in stand-off distance due to poor jet contact.
This study was designed to investigate the effect of terpenoid fraction of Physalis angulata on c... more This study was designed to investigate the effect of terpenoid fraction of Physalis angulata on cardiovascular and renal parameters with a total of 20 male albino rats. These were determined using spectrophotometric methods. The rats were randomly divided into four groups of five (5) rats each. Group 1: was not administered with anything (Normal Control); Group 2: was administered with 50 mg/Kg b. w of vitamin C (standard drug); Group 3: was administered with 25 mg/Kg b. w of the isolated terpenoids; Group 4: was administered with 50 mg/Kg b. w. of the isolated terpenoids; Group 5: was administered with 100 mg/Kg b. w. of the isolated terpenoids for the period of 30 days. All the rats were given free access to water and commercial poultry feed ad libitum. Results of the analyses were expressed as mean ± standard deviation. Relative to the control group, the serum creatine kinase and lactate dehydrogenase activities increased non-significantly (p>0.05) with dose among groups of ra...
This study was carried out to investigate the toxicological properties of terpenoids fraction of ... more This study was carried out to investigate the toxicological properties of terpenoids fraction of Physalis angulata in male albino rats. These were determined using spectrophotometric methods. The rats were randomly divided into four groups of five (5) rats each. Group 1: was not administered with anything (Normal Control); Group 2: was administered with 50 mg/Kg b. w of vitamin C (standard drug); Group 3: was administered with 25 mg/Kg b. w of the isolated terpenoids; Group 4: was administered with 50 mg/Kg b. w. of the isolated terpenoids; Group 5: was administered with 100 mg/Kg b. w. of the isolated terpenoids for the period of 30 days. All the rats were given free access to water and commercial poultry feed ad libitum. Results of the analyses were expressed as mean ± standard deviation. The acute toxicity study of the root extract was performed using the acute oral toxicity up and down method and the result of the study showed no mortality of the animals used even at the highest...
Day 3 Wed, August 04, 2021, 2021
Despite the recent wide embrace of mechanical descaling approaches for cleaning scales in petrole... more Despite the recent wide embrace of mechanical descaling approaches for cleaning scales in petroleum production tubings and similar conduits with the use of high-pressure (HP) water jets, the process is still associated with downhole backpressure and well integrity challenges. While the introduction of sterling beads to replace sand particles in the water recorded high successes in maintaining well completion integrity after scale removal in some recent applications of this technique, it is, unfortunately, still not without questions of environmental degradation. Furthermore, the single nozzle, solids-free, aerated jetting descaling technique – recently published widely – is categorized with low scale surface area of contact, low descaling efficiency and subsequent high descaling rig time. The modifications to mechanical descaling techniques proposed in this work involve the use of three high-pressure flat fan nozzles of varying nozzles arrangements, standoff distances and injection ...
The main focus of this thesis is to evaluate kr(n, δ), the minimal number of r-cliques in graphs ... more The main focus of this thesis is to evaluate kr(n, δ), the minimal number of r-cliques in graphs with n vertices and minimum degree δ. A fundamental result in Graph Theory states that a triangle-free graph of order n has at most n/4 edges. Hence, a triangle-free graph has minimum degree at most n/2, so if k3(n, δ) = 0 then δ ≤ n/2. For n/2 ≤ δ ≤ 4n/5, I have evaluated kr(n, δ) and determined the structures of the extremal graphs. For δ ≥ 4n/5, I give a conjecture on kr(n, δ), as well as the structures of these extremal graphs. Moreover, I have proved various partial results that support this conjecture. Let k r (n, δ) be the analogous version of kr(n, δ) for regular graphs. Notice that there exist n and δ such that kr(n, δ) = 0 but k reg r (n, δ) > 0. For example, a theorem of Andrasfai, Erdős and Sos states that any triangle-free graph of order n with minimum degree greater than 2n/5 must be bipartite. Hence k3(n, bn/2c) = 0 but k 3 (n, bn/2c) > 0 for n odd. I have evaluated ...
Journal of Petroleum and Gas Engineering, 2021
The mechanical approach of utilizing high-pressure water for scale removal has gained wider accep... more The mechanical approach of utilizing high-pressure water for scale removal has gained wider acceptance by multinationals despite facing poor downhole performance challenges (cavitation) that need abrasion compensation (sand) with side effect of jeopardizing the integrity of the well completions. The replacement of sand with sterling beads was excellent with good post descaling well completion integrity at the expense of environmental complexity. While the recent single nozzle, solid free aerated jetting descaling technique was characterized with poor scale coverage and high descaling time. This investigation presents the novel technique of scale removal utilizing multiple high-pressure flat fan nozzles at different distances, nozzle configurations and injection pressure to remove soft scale sample made of paraffin. The scale shaped in two different patterns of hollow and solid signifying different growth stages of paraffin in production tubing. The results at 25 mm stand-off distances showed that the scale removal was within the range of 0.8 to 42.8 g (for hollow shape scale) and 0.3 to 5.2 g (for solid shape scale) at 4.8 MPa with different nozzle configurations. Increasing the injection pressure to 6 MPa removed more scale within the range of 1.1 to 93.7 g (for hollow shape scale) and 0.7 to 7.3 g (for solid shape scale). Moreover, at 10 MPa injection pressure the scale removal was within the range of 1.1 to 253.8 g (for hollow shape scale) and 1.1 to 103.7 g (for solid shape scale). This result will provide a practical approach to the removal of organic scales at varying descaling conditions of injection pressure, standoff distance and nozzle configurations.
Journal of Petroleum Science and Engineering, 2021
Several researchers employed N2 to augment CH4 recovery efficiency and CO2 sequestration during t... more Several researchers employed N2 to augment CH4 recovery efficiency and CO2 sequestration during the Enhanced Gas Recovery (EGR) process in consolidated rocks. To our knowledge, there has been limited data backing the reason why CO2 experienced a more extended breakthrough during the EGR process in the presence of N2 gas. This study inves-tigated CO2 and N2 behaviour during the core flooding experiment by CO2 injection in Bentheimer core plug. N2 was used as the continuous phase during the core flooding process, while CO2 was the dispersed phase. The experiment was designed with varying injection rates at 30 and 40 0C temperature points. The experimental findings showed that the dispersion and diffusion coefficient, CO2 storage, concentration profile and breakthroughs were highly influenced by temperature change, especially at lower injection rates. However, at high injections, those properties are less sensitive to change in temperature, with most of the curves overlapping in the concentration profile. The highest and most negligible dispersion and diffusion coefficients were recorded at the highest and lowest injection rates respec-tively. These results agree with those reported by several researchers for sandstone rocks. Thus, higher temperatures have a more substantial effect on dispersion and diffusion coefficient, which eventually led to higher mixing between CO2 and N2. The breakthrough time decreases with an increase in reservoir temperature, confirming the diffusion and dispersion coefficients are temperature dependent. The experiment at 30 0C recorded an extended breakthrough time over that at 40 0C. The maximum breakthrough time at 0.52 PV was recorded at 30 0C at the lowest injection rate. The concentration profile highlighted the trend between the displacing and displaced gas during the core flooding experiment. From the range of injections and temperatures tested, the CO2 PV stored decreases as the rate of injection increases from 0.4 – 1.2 ml/min. However, the CO2 stored was more promising at higher rates, corresponding with high differential pressure, due to flow resistance within the tortuous flow channels in the porous medium
Journal of Natural Gas Science and Engineering, 2020
The choice of the flow velocity in EGR thus becomes important since higher injection rates could ... more The choice of the flow velocity in EGR thus becomes important since higher injection rates could lead to premature mixing of the fluids and lower injection rates generally provide longer resident times for the fluids in contact and indirectly increases the mixing of the gases. Additionally, the medium peclet numbers mostly indicate the best injection rates that translate to a smoother displacement with a lower dispersion coefficient during the EGR process. Therefore, N2 Injection into natural gas reservoirs offers the potential to higher recovery efficiency with less mixing compared to conventional CO2 injection. The atmospheric air contained 79% of N2, making it readily available than CO2 with 400 ppm air composition. More so, N2 requires less compression ratio, which is why a lower amount of it was required to initiate much pressure in the CH4 reservoir during displacement. These made the use of N2 more economically feasible and friendly for the EGR process. A laboratory core flooding experiment was carried out to simulate the effect of injection velocity on CH4 recovery and dispersion coefficient. This was done at 40 0 C, 1500 psig, and 0.2-1.0 ml/min injection rates. The results showed that a medium peclet number could be used to predict the best injection rate that translates to a smoother displacement with a lower dispersion coefficient during the EGR process. CH4 recovery and efficiency were highest at lower injection velocities experienced in both core samples. This could be attributted to insignificance nascent mixing observed as seen on their recorded low longitudinal dispersion coefficient results. Consequence, the experimental runs at high injection rates (0.6-1.0 ml/min) present a different scenario with lower recovery and efficiency due to their high interstitial velocities as the N2 plumes transverses into the core sample during CH4 displacement. Overall, the least methane production and efficiency were noticed in the Bandera core sample as a result of the heterogeneity effect due to the presence of higher clay contents in Bandera than Berea gray. When the capillary forces within the narrower pores in Bandera core sample were overcome, the clay particles occupied those pores thereby sealing some of the flow paths within the pore matrix. This reduces the flow channels, significantly, through which the injected N2 will flow to displace the residual CH4.
Journal of Petroleum Exploration and Production Technology, 2020
The promotion of enhanced gas recovery (EGR) and CO2 storage is still shrouded in contention and ... more The promotion of enhanced gas recovery (EGR) and CO2 storage is still shrouded in contention and is not well accepted, due to the excessive in situ CO2 mixing with the nascent natural gas. This adulterates the recovered CH4 and thus results in a high sweetening process cost thereby making the technique impractical. This has not only limited the field application of EGR in actual projects to a few trails but renders it uneconomical. This study aims to present, experimentally, alternating N2 injection as a potential technique for EGR and CO2 storage in sandstone rock cores. A laboratory core flooding experiment was carried out to simulate a detailed process of unsteady-state methane (CH4) displacement using Bandera grey core plug. This was carried out at 40 °C, 1500 psig, and 0.4 ml/min injection rate by alternative injection of N2 and CO2 in succession designed to suit the application based on optimum operating conditions. The results show that both CO2 storage capacity and CH4 recov...
Journal of Natural Gas Science and Engineering, 2019
This study aims to experimentally investigate the potential of solubility trapping mechanism in i... more This study aims to experimentally investigate the potential of solubility trapping mechanism in increasing CO2 storage during EGR by CO2 injection and sequestration in conventional natural gas reservoirs. A laboratory core flooding process was carried out to simulate EGR on a sandstone core at 0, 5, 10wt% NaCl formation water salinity at 1300 psig, 50 o C and 0.3ml/min injection rate. The results show that CO2 storage capacity was improved significantly when solubility trapping was considered. Lower connate water salinities (0 and 5 wt%) showed higher CO2 solubility from IFT measurements. With 10% connate water salinity, the highest accumulation of the CO2 in the reservoir was realised with about 70% of the total CO2 injected stored; an indication of improved storage capacity. Therefore, solubility trapping can potentially increase the CO2 storage capacity of the gas reservoir by serving as a secondary trapping mechanism in addition to the primary structural and stratigraphic trapping and improving CH4 recovery.
IOSR Journal of Pharmacy and Biological Sciences, 2014
The effects of Hevea bransiliensis natural rubber on weight gain and plasma cholesterol concentra... more The effects of Hevea bransiliensis natural rubber on weight gain and plasma cholesterol concentration of experimental rats were analyzed. Forty albino wister rats of either sex weighing 140-450g were used. The rats were divided into five equal groups marked A, B, C, D and E of eight rats each, and each group was fed on different dietary regime A, B, C, D and E respectively as indicated in tables 1 and 2. Diet A, (the control) had no rubber seed oil in the diet, whereas diets B, C, D and E (the experimental) had 2% refined rubber seed oil, 2% crude rubber seed oil, 4% refined rubber seed oil and 4% crude rubber seed oil by weight incorporated respectively. The results showed a general increase in mean weight with duration of feeding. Group D (4% refined rubber seed oil incorporated in the diet) showed more rapid increase in mean weights than groups E (4% crude rubber seed oil) and A (the control no rubber seed oil). The results also indicated a general increase in total and free plasma cholesterol levels of the rats within eight weeks duration of the feeding and fall during the remaining four weeks.
IOSR Journal of Dental and Medical Sciences, 2014
The effects of Hevea bransiliensis natural rubber on phospholipid concentrations of experimental ... more The effects of Hevea bransiliensis natural rubber on phospholipid concentrations of experimental rats were analyzed. Forty albino wister rats of either sex weighing 140-450g were used. The rats were divided into five equal groups marked A, B, C, D and E of eight rats each, and each group was fed on different dietary regime A, B, C, D and E respectively as indicated in tables 1 and 2. Diet A, (the control) had no rubber seed oil in the diet, whereas diets B, C, D and E (the experimental) had 2% refined rubber seed oil, 2% crude rubber seed oil, 4% refined rubber seed oil and 4% crude rubber seed oil by weight incorporated respectively. The results showed an increase in plasma phosphatide level for groups B and A rats. Little increase in plasma phosphatide levels were found in groups D, C and E rats. The results of liver phospholipids showed an increase in phospholipids concentration of groups C, D and E rats compared to groups B and A (control) for the corresponding weeks.
Metallic Glasses - Properties and Processing, 2018
A fundamental quest of modern triboelectrochemistry is to unravel the prevailing failure mechanis... more A fundamental quest of modern triboelectrochemistry is to unravel the prevailing failure mechanisms when surface interactions are operated in corrosive environments and to study how these influence the performance of materials and tools. Both system and materials oriented approaches are thus required to deal with the electrochemical and physicochemical changes of matter due to the influence of a mechanical sliding energy between the two contacting surfaces (i.e. tribocorrosion damage). In this chapter, metallic glass material concepts used in environments where tribocorrosion occurs are described. Concepts to act in opposition to wear and corrosion are briefly reported. In particular, a description is given of different groups of metallic glasses designed to withstand the effects of combined and uncoupled wear and corrosion. Metallic glass composition, structural effect, crystallization level, passive film formation, microhardness are often viewed as the most critical elements in the performance of tribocorrosion of metallic glasses. Interactions between wear and corrosion mechanisms are identified along with some models that aim to inform metallic glass selection and predict performance.
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Papers by Salihu Suleiman