The Effect of Surfactant Characteristics on IFT to Improve Oil Recovery in Tempino Light Oil Field Indonesia

Water injection has been employed in the Tempino oil field since 1996. The current oil recovery factor is 35% of OOIP. Even though the pressure is still high, the oil production rate has declined rapidly and the water cut is approaching 89%. In order to mobilize  the  oil from the  reservoir  more effectively, surfactant flooding is one of the solutions that can reduce residual oil saturation. Interaction between crude oil and compatible surfactant generates microemulsion,  as an indication of low interfacial tension. Hence the oil is expected to move out of the pore throat easily. In this research, thirty types of surfactants  were evaluated. The hydrophilic  lipophilic  balance (HLB)  was calculated and  the  interfacial tension (IFT)  with the  reservoir fluid  was measured. HLB criteria were established as an indicator of low IFT, which was then tested for Berea core flooding. The results indicate that an HLB between approximately 2.7 and 3.1 (on Davies' Scale) or greater than 11.5 (on Griffin's Scale) gives  low IFT  (~10-3 dynes/cm).  This characteristic  is possesed by surfactant  ethoxy  carboxylate  with a  linear hydrophobic structure.  This surfactant produces a high incremental oil recovery according to Berea core flood tests. The AN2NS and AN3 surfactants recovered 90% and 86% of OOIP respectively

Determination of Gas Pressure Distribution in a Pipeline Network using the Broyden Method

A potential problem in natural gas pipeline networks is bottlenecks occurring in the flow system due to unexpected high pressure at the pipeline network junctions resulting in inaccurate quantity and quality (pressure) at the end user outlets. The gas operator should be able to measure the pressure distribution in its network so the consumers can expect adequate gas quality and quantity obtained at their outlets. In this paper, a new approach to determine the gas pressure distribution in a pipeline network is proposed. A practical and user-friendly software application was developed. The network was modeled as a collection of node pressures and edge flows. The steady state gas flow equations Panhandle A, Panhandle B and Weymouth to represent flow in pipes of different sizes and a valve and regulator equation were considered. The obtained system consists of a set of nonlinear equations of node pressures and edge flowrates. Application in a network in the field involving a large number of outlets will result in a large system of nonlinear equations to be solved. In this study, the Broyden method was used for solving the system of equations. It showed satisfactory performance when implemented with field data

Solusi Model Aliran Gas Dalam Pipa pada Kondisi Line Packing Menggunakan Skema Richtmyer

Line packing is a process storing gas in pipeline by increasing inlet gas flow rate while outlet gas flow rate is kept constant. This difference of gas flow rate causes the gas flow in pipeline being transient. Line packing process is intended to guarantee gas supply when trouble occurs. In this paper, a transient model with boundary condition is solved numerically using Richtmyer scheme, because stability analysis showed that Richtmyer scheme is better than other explicit schemes. In the case presented, it is shown that Richtmyer scheme sufficiently agrees with the real data in gas pipeline transmission, which is in many cases unsteady-state

Improved Joule Thomson equation of supercritical CO2-rich natural gas in separation system

The rapid expansion of supercritical gas technology for high-content CO2 separation from natural gas is a promising avenue of research. However, CO2-rich natural gas cools immediately after being separated and expands when the CO2 dew point is reached in the absence of a refrigerant system. In our previous study, supercritical expansion experiments using various CO2 compositions revealed that the Joule–Thomson equation gives a significant absolute average error value of 16.28%. This paper describes corrections to the Joule–Thomson expansion equation under supercritical conditions with various CO2 concentrations. The results show that the trend of the expansion coefficient is highly dependent on the CO2 composition. Using an improved Joule–Thomson equation of state over a CO2 range of 25%–45% mol, the expansion coefficient tends to fall immediately when a rapid expansion occurs. For a supercritical fluid, the specific heat Cp depends on temperature, pressure, and density changes. The Van der Waals expansion coefficient profile is simulated using MATLAB, resulting in a correction factor of 1.17–1.32 being applied to the Cp value for CO2 concentrations of 25%–40% mol, whereby the absolute average error tends to zero. For CO2 concentrations of more than 40%, the Joule–Thomson equation cannot be applied because the expansion coefficient exhibits significant errors compared with the experimental data. The expansion coefficient does not directly determine the performance of supercritical expansion, but does affect the vapor fraction. Integrated production systems based on supercritical expansion are expected to produce an annual profit of around US$18 million from turbine expansion and US$489 million from the production of sweet gas with a purity of 96.6% and less than 2% mol CO2

Determination of Gas Pressure Distribution in a Pipeline Network using the Broyden Method

A potential problem in natural gas pipeline networks is bottlenecks occurring in the flow system due to unexpected high pressure at the pipeline network junctions resulting in inaccurate quantity and quality (pressure) at the end user outlets. The gas operator should be able to measure the pressure distribution in its network so the consumers can expect adequate gas quality and quantity obtained at their outlets. In this paper, a new approach to determine the gas pressure distribution in a pipeline network is proposed. A practical and user-friendly software application was developed. The network was modeled as a collection of node pressures and edge flows. The steady state gas flow equations Panhandle A, Panhandle B and Weymouth to represent flow in pipes of different sizes and a valve and regulator equation were considered. The obtained system consists of a set of nonlinear equations of node pressures and edge flowrates. Application in a network in the field involving a large number of outlets will result in a large system of nonlinear equations to be solved. In this study, the Broyden method was used for solving the system of equations. It showed satisfactory performance when implemented with field data

Solusi Model Aliran Gas Dalam Pipa pada Kondisi Line Packing Menggunakan Skema Richtmyer

Line packing is a process storing gas in pipeline by increasing inlet gas flow rate while outlet gas flow rate is kept constant. This difference of gas flow rate causes the gas flow in pipeline being transient. Line packing process is intended to guarantee gas supply when trouble occurs. In this paper, a transient model with boundary condition is solved numerically using Richtmyer scheme, because stability analysis showed that Richtmyer scheme is better than other explicit schemes. In the case presented, it is shown that Richtmyer scheme sufficiently agrees with the real data in gas pipeline transmission, which is in many cases unsteady-state