Hydrocarbon Reservoirs Management
TEMPLE N CHIKWE; Remy Ukachukwu Duru
Abstract
The Asphaltene and metal naphthenate components of crude oil samples from ten different wells within an oil reservoir were determined using different analytical techniques. The asphaltene content was determined by gravimetric analyses while the metal naphthenate components were determined by obtaining ...
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The Asphaltene and metal naphthenate components of crude oil samples from ten different wells within an oil reservoir were determined using different analytical techniques. The asphaltene content was determined by gravimetric analyses while the metal naphthenate components were determined by obtaining the metal ion concentration of the produced water and the naphthenic acid concentration of the crude using Atomic absorption spectrometer (AAS) and potentiometric titration respectively. Results obtained showed that the asphaltene content of the crude samples ranges from 2.0000 – 8.000 %w while the naphthenic acid concentration indicated by the total acid number (TAN) ranges from 0.3000 – 1.4600 mg/KOH/g. All the crude samples possess asphaltene components as well as the propensity to form calcium and sodium naphthenate scale deposits having a Ca2+ concentration between 32.5000 – 94.5000 mg/L and a Na+ concentration between 27.7 – 105.1 mg/L respectively, however the formation of naphthenate scale deposits is highly dependent on the pH of the produced water of the crude which makes well FT01 less likely to form naphthenate scales since it has a pH < 6. Both asphaltene and naphthenate deposits are directly proportional to the specific gravity of the crude and inversely proportional to the API gravity implying that both components reduce the quality of the crude. Asphaltene and metal naphthenate solid deposits in the crude can cause a lot of flow assurance difficulties such as, blocking of expedition lines, pore plugging, wettability, crude oil parameter alteration, as well as reduction in oil recovery.
Jalal Neshat; Seyed Reza Shadizadeh
Abstract
The unwanted addition of salt to drilling causes flocculation which has an adverse effect on mud rheological properties. To treat the flocculated mud chemical, deflocculants are commonly used; however, their disadvantages such as negative environmental effects, lower tolerance to contamination, and toxicity ...
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The unwanted addition of salt to drilling causes flocculation which has an adverse effect on mud rheological properties. To treat the flocculated mud chemical, deflocculants are commonly used; however, their disadvantages such as negative environmental effects, lower tolerance to contamination, and toxicity motivated scientists to search for effective additives. Using plant derived additives instead of commercial additives could help resolve the mentioned weaknesses, because they are nontoxic, cheap, easily accessible, and act multi-functional. In this paper the effect of black myrobalan rheological properties of flocculated bentonite mud was investigated and its performance was compared with chrome lignosulfonate (CLS). Rheological and filtration tests were conducted and properties such as plastic viscosity, yield point, gel strength, thixotropy, and apparent viscosity were calculated. It was perceived that by increasing black myrobalan concentration to 0.6 wt.%, rheological parameters and filtration loss decreased by 50% and 66.3% respectively, but they increased at higher concentrations, which indicated that black myrobalan acted as a deflocculant up to 0.6 wt.%. The deflocculation behavior of black myrobalan at low concentrations is attributed to ellagitannic acid and tannic acid. The comparison of the enactment of black myrobalan with chrome lignosulfonate showed that black myrobalan had a stronger decreasing effect on the rheological parameters and filtration compared to CLS.