Chapters authored
Temperature Effect on Shear Thinning Behavior of Low-Viscous Oilfield Emulsion
Crude oil emulsion is causing a lot of problems, especially during crude oil production. There are many ways to mitigate the emulsion problems but this leads to an increment in operating expenses of oil production. In order to comply with the standard sales oil quality, crude oil emulsion must be treated properly. Hence, better understanding of emulsion is essential since emulsion can be available in almost all phases of oil production and processing. This chapter describes how temperature parameters would affect the rheological property of a low-viscous emulsion and how it would become a significant point associated with stability of crude oil emulsion in oilfield production. Experimental results indicated that the water-in-crude oil emulsion formed from low-viscous crude oil exhibits a non-Newtonian shear thinning behavior, which was best presented by the Herschel-Bulkley rheological model. Temperature ranges from 20 to 90°C were examined to study the effect of temperature toward shear stress and viscosity of oilfield emulsion. Measurement of shear stress at shear rates higher than 600 s−1 is a new direction in rheology study that not much is known about its effect on shear stress.
Part of the book: Science and Technology Behind Nanoemulsions
Evaluation of Asphaltenes Deposition Inhibition Factors in Heavy Crude Oil Pipelines
Asphaltenes deposition is considered as Achilles’s heel in the oil industry. The nucleation, precipitation and deposition of asphaltenes reduce the production rate significantly in affected wells and sometimes it can completely block the flow by plugging the flowlines, tubing and process facilities, in severe cases. This chapter evaluates the extrinsic and the intrinsic (thermodynamic) factors within the heavy crude oil production system. The main consequences of asphaltenes deposition are discussed such as the solvent-to-crude oil dilution ratio, crude oil physical properties (cloud point, pour point and API gravity), chemical solvent type (carbon number, functional group), agitation time and temperature changes. This chapter is expected to become the means for understanding the factors affecting the asphaltenes nucleation, precipitation and deposition.
Part of the book: Processing of Heavy Crude Oils
Challenges during Operation and Shutdown of Waxy Crude Pipelines
Transportation of waxy crude oil faces great challenges due to shear and temperature dependency. At high temperatures, waxy crude exhibits low viscous Newtonian behavior where the resistance to flow due to friction is low, and hence low pumping pressure is required to transport it. At low temperatures, however, the crude exhibits shear thinning non-Newtonian behavior where its apparent viscosity becomes shear-dependent. In such cases, the operated pipeline needs to maintain a high pressure to guarantee a continuous flow. Moreover, due to heat transfer between the internal pipeline and surroundings, oil temperature declines along the pipeline. It follows that the crude viscosity and, hence, frictional resistance increase. If the flow is interrupted for any reason, i.e., emergency or planned shutdown, then the restartability of the pipeline becomes a challenge because of the nonexistence of heating generated from friction. In this chapter, the challenges normally facing transportation of waxy crude oil will be discussed. The chapter will introduce the rheological properties of waxy crude oil and explain and describe how these properties can affect the pressure losses inside the pipeline during its operation and shutdown. The measures that need to be considered when designing a waxy crude pipeline will be discussed.
Part of the book: Processing of Heavy Crude Oils