6 Jul, 2015

'Building a High-Performance Facilities Engineering Organization' is now available for download

This paper presents a methodology for constructing a Facilities Engineering organization for an Upstream-Midstream operating company. The methodology encompasses 7 main elements.

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2 Jun, 2015

Effect of Chemical Additive on Crude Oil Pipeline Pressure Drop

For transportation of crude oil, the pumping power requirement varies as the crude oil viscosity changes. Increasing °API or line average temperature reduces the crude oil viscosity. The reduction of viscosity results in higher Reynolds number, lower friction factor and in effect, lower pumping power requirements. To reduce pressure drop and increase pipeline capacity, oil industry has utilized drag reducing agents. Drag-reducing agents, or drag-reducing polymers, are additives in pipelines that reduce turbulence in a pipe. Usually used in petroleum pipelines, they increase the pipeline capacity by reducing turbulence and therefore allowing the oil to flow more efficiently. In addition to drag reducing agents, another group of chemicals called “Incorporative Additives”, which reduces crude oil viscosity, may be used. In this Tip of the Month, we will demonstrate the effect of an incorporative additive on crude oil viscosity and consequently on pressure drop for crude oil pipeline transportation.

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4 May, 2015

Benefits of Standby Time in Adsorption Dehydration Process

Molecular sieves are used upstream of turboexpander units and LNG facilities to dehydrate natural gas to <0.1 ppmv. In the natural gas industry, the molecular sieves employ heat to drive off the adsorbed water. The cyclical heating/cooling of the adsorbent results in a capacity decline due to a gradual loss of crystalline structure and/or pore closure. A more troublesome cause of capacity decline is contamination of the molecular sieves due to liquid carryover from the upstream separation equipment. Because of the capacity decline curves flatten out, available standby time may be able to extend the life of a molecular sieve unit when your unit is operating on fixed cycle times. Other operating options include: running each cycle to water breakthrough; and, reducing the cycle times in discreet steps throughout the life of the adsorbent. To illustrate the benefits of standby time, a case study was evaluated and the results are presented.

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10 Apr, 2015

Estimating Sour Gas Water Content by New Correlations and Simplified Charts

In April's "Tip of the Month," we will present a set of correlations and simplified charts for estimating sour gas water content directly without having to look up the water content of sweet gas. These correlations are based on the Wichert and Wichert chart (Figure 20-9 of the GPSA data book) and Wagner and Pruss water vapor equation and Bukacek correlation for estimating sweet gas water content. The proposed correlations are valid for pressures up to 24 MPa (3500 psia), temperatures up to 175°C (350°F) and H2S equivalent concentrations of up to 50 mole %. The accuracy of the proposed correlations was compared against limited experimental data and a rigorous method using an equation of state.

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12 Feb, 2015

Why CO2 Flashing from Water is Important for CO2 EOR Flood Separators and Tanks

In this Tip of the Month (TOTM) we will discuss how to determine CO2 solubility and flashing issues in water at pressures and temperatures commonly associated with gathering systems and production facilities. This is mainly important for CO2 Enhanced Oil Recovery (EOR) floods as the CO2 concentration is high and the initial separation is at higher pressures than is common in non-CO2 EOR oilfields. These two conditions result in significant dissolving of CO2 into the produced water with resultant flash gas from downstream Free Water Knockouts (FWKO), treaters, and tanks. In mature CO2 EOR floods with Water-Alternating-Gas (WAG) injection schemes, it is likely that most of the flash gas in the downstream separations will be from the produced water. While this TOTM is significant mainly for CO2 EOR floods, the following analysis is general in nature; it would apply to other situations involving CO2 solubility in water issues. This analysis assumes that there is no H2S. H2S would have somewhat higher solubility than CO2 which would force more gas to flash from the FWKO and tanks. Higher H2S than about 5% would begin to appreciably increase the solubility of H2S into water.

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