A.K.M. Jamaluddin

Linearity of Near-Infrared Spectra of Alkanes

Near-infrared (NIR) spectroscopy is used to monitor a large variety of process flow streams. Hydrocarbons with their strong and resolvable NIR spectral signatures are good candidate analytes. NIR has been exploited to monitor many chemical properties for optimal hydrocarbon utilization particularly for well-characterized flow streams of small variability for end users. The utility of NIR in the context of the production of hydrocarbon resources necessitates application over a much broader range of flow stream conditions. Here we examine the spectral impact of variable temperature, pressure, and composition to determine the robustness of NIR methods in upstream applications.

Deasphalted Oil - A Natural Asphaltene Solvent

Asphaltene deposition in the near-wellbore region can block pore throats, change wettability characteristics and relative-permeability relationships, and therefore, reduce oil production. Conventional aromatic solvents (e.g., toluene and xylene) alone or in combination with various dispersants are used to remove asphaltene damage from the near-wellbore region. However, these aromatic solvents are expensive and are not environmentally friendly. The objective of this work was to systematically evaluate the asphaltene-solvating power of various nonconventional solvents, including deasphalted oil, using a light-scattering technique. Experimental results suggest that deasphalted oil is a strong asphaltene solvent presumably because of its native resin and aromatic contents. Addition of asphaltene dispersants also increases the solubilizing power of the deasphalted oil. Furthermore, various refinery and heavy oil upgrader streams show strong ability to solubilize asphaltenes.

Impact of Flow Assurance in the Development of a Deepwater Prospect

In deepwater production systems, extreme pressure and temperature conditions, multipart sub-sea networks, complex reservoir characteristics, and various fluid phases flowing from the reservoir rock to the surface could promote production interruption due to the formation and deposition of hydrocarbon solids such as asphaltene, wax and hydrates anywhere in the production system. These are flow assurance key risk factors that create significant impact on field development planning, especially, when dealing with marginal deposits having varying fluid characteristics. To reduce the risk, we have adopted a systematic approach to evaluate the potential impact of asphaltene and wax precipitation and deposition.

Waxy Crude Production Management in a Deepwater Subsea Environment

Summary Systematic experimental and modeling approaches to designing a safe operating strategy for a 5-km deepwater-subsea-flowline case study are presented to address unplanned shutdown and restart events for waxy-crude production. The measurements confirmed that the fluid behaves like Bingham plastic when it is allowed to become gel at the seabed temperature of 4°C. The cool-down period was modeled using the transient simulator validated by measurements and was predicted to take 21 hours. The restart pressure was then modeled for both stock-tank and at-line pressure conditions. These restart pressure requirements were found to be 2,500 and 2,100 psi, respectively, for stock-tank and at-line pressure conditions. Also, the use of pour-point depressants demonstrated that the fluid would not form gel at the seabed temperature of 4°C. However, the current shut-in wellhead pressure of 2,500 psi is deemed adequate to restart the lines in the event of unplanned shutdown without the use of chemicals. The presence of a subsea pig-launching pump provides a safety factor for restart in case the line pressure is released to atmospheric conditions. Hence, the operating strategy does not require injection of pour-point depressants at the current state. However, in future when the shut-in wellhead pressure falls below 2,500 psi, the operating strategy is expected to be modified accordingly.