Claim Missing Document
Check
Articles

Found 2 Documents
Search

Wax Precipitation in Crude Oil by Coutinho Model Based on Conventional Gas Chromatography Data Muh Kurniawan; Adiwar Adiwar; Kamarza Mulia; Chairil Anwar
Scientific Contributions Oil and Gas Vol 36 No 2 (2013)
Publisher : Testing Center for Oil and Gas LEMIGAS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29017/SCOG.36.2.764

Abstract

Wax precipitation in crude oils can produce problems in oil production and transportation operations. Prediction is the key of avoidance or remediation of the wax problem of flow assurance. Among the wax prediction thermodynamic model, Coutinho model can be run using limited laboratory data, but the result is comparably accurate. The model requires n-paraffin distribution, which commonly determined by high-temperature gas chromatography (HTGC) analysis. However, only few laboratories could perform the HTGC. Lemigas has abundant database of crude oil with conventional gas chromatography data. An extended n-paraffin distribution was calculated based on the conventional GC data by performing extrapolation and normalization to total wax content. The n-paraffin distribution was applied in Coutinho model to predict wax precipitation of a crude oil sample. The WAT obtained from the model deviated only 2°C from DSC data. The result was also valid to DSC data in term of precipitated wax amount along temperature range.
Effects Of Delayed Evaporation In Cellulose Acetate Membrane Preparation To Separate Co2/Ch4 At Low Pressure Adiwar Adiwar
Scientific Contributions Oil and Gas Vol 32 No 3 (2009)
Publisher : Testing Center for Oil and Gas LEMIGAS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29017/SCOG.32.3.847

Abstract

The effect of delayed evaporation rate on CO2/CH4 selectivity was investigated on cellulose acetate based membrane in composition of cellulose acetate and acetone (CA+ACE), cellulose acetate, acetone and formamide (CA+ACE+F) and cellulose acetate, acetone, formamide and polyethylene glycol 400 (CA+ACE+F+PEG). Delayed evaporation was carried out in acetone saturated air. The study shows that the presence of PEG in membrane composition gives a probability for the membrane to be used and kept in dry state. Evaporation time at standard evaporation rate for membrane composition CA+ACE+F andd CA+ACE+F+PEG to get better selectivity is not less than 60 seconds. SEM shows that macrovoids in membrane prepared by delayed evaporation rate compared to those prepared by standard evaporation are smaller in size but higher in numbers.Effects of 60 seconds of delayed evaporation rate on membrane selectivity and permeability is about the same with the effects of 15 seconds of standard evaporation. It brought abourt, in turn, a thought, that the effects of 8 seconds evaporation in spineret on hollow fibre selectivity and permeability can be increased by increasing evaporation rate.