Category Archives: Refining

Correlations for Conversion between True and Reid Vapor Pressures (TVP and RVP)

Written on February 1, 2016 at 4:02 pm, by

Accurate measurement and prediction of crude oil and natural gas liquid (NGL) products vapor pressure are important for safe storage and transportation, custody transfer, minimizing vaporization losses and environmental protection. Vapor pressure specifications are typically stated in Reid Vapor Pressure (RVP) or/and True Vapor Pressure (TVP). In addition to the standard procedures for their measurements,Continue Reading

Adsorption Dehydration: Two-Tower vs Three-Tower System

Written on November 1, 2015 at 12:00 am, by

There are different process configurations for adsorption dehydration systems. The most common arrangements are two-tower and three-tower configurations. One can find the details of the adsorption dehydration process and the descriptions of equipment in Chapter 18 of John M. Campbell textbook [1]. Figures 1 and 2 present a simplified process flow diagram for two-tower andContinue Reading

Gas-Liquid Separators Sizing Parameter

Written on September 1, 2015 at 12:00 am, by

Download PDF Version In the December 2014 tip of the month (TOTM) [1], we discussed troubleshooting of gas-liquid separators for removal of liquids from the gas stream leaving the separator. There are two methods for sizing gas-liquid separators: 1. Droplet settling theory method, 2. Souders-Brown approach. Historically the Souders-Brown equation has been employed as itContinue Reading

Effect of Relative Density (Specific Gravity) on the Saturated Water Content of Sweet Natural Gases

Written on August 1, 2015 at 12:00 am, by

In the past Tips of the Month (TOTM), we discussed the phase behavior and water content of lean sweet, sour natural gases and acid gases–water systems. Specifically, in the November 2007 [1], February 2014 [2], and September 2014 [3] Tips of the Month (TOTM), we discussed the phase behavior of water-saturated sour gases and acidContinue Reading

Effect of Chemical Additive on Crude Oil Pipeline Pressure Drop

Written on June 1, 2015 at 12:00 am, by

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. In the March 2009 tip of the month (TOTM),Continue Reading

Benefits of Standby Time in Adsorption Dehydration Process

Written on May 1, 2015 at 12:00 am, by

Molecular sieves are used upstream of turboexpander units and LNG facilities to dehydrate natural gas to <0.1 ppmv water content.   In the natural gas industry, the molecular sieves employ heat to drive off the adsorbed water.  Figure 1 shows a typical flow schematic for a 2 tower system; Figure 2 shows a 3 tower system.Continue Reading

Process Safety and Low Oil Prices

Written on March 1, 2015 at 12:00 am, by

In this Tip of the Month, we reflect back to December 2008, and get a reminder from the United States Chemical Safety Board (CSB) to remain focused on process safety and accident prevention during this time of lower oil prices. During the economic downturn of 2008, oil prices dropped significantly. The latest drop in crudeContinue Reading

Troubleshooting Gas-Liquid Separators – Removal of Liquids from the Gas

Written on December 1, 2014 at 12:00 am, by

One of the most common problems in Oil and Gas Processing facilities is underperforming vapor / liquid separators. The most common types of gas-liquid separators are: Slug catchers Vessel / Finger-type “Conventional” separators Vertical / Horizontal Scrubbers (i.e. Compressor Suction Scrubbers) Gas “polishers” Coalescing Filters / Filter Separators Underperforming separators generally result from either: 1.Continue Reading

Impact of Gas-Oil Ratio (GOR) on Crude Oil Pressure Drop in Gathering Systems

Written on October 1, 2014 at 9:00 am, by

The use of multiphase flow systems is common practice in the oil and gas industry. Multiphase flow is often encountered in the well tubing, flow lines and gathering systems. For transport of oil and gas (and water) to downstream processing facilities the preference is normally a single pipeline in which both phases are transported simultaneouslyContinue Reading

Lean Sweet Natural Gas Water Content Correlation

Written on September 1, 2014 at 12:00 am, by

In the October, November, December 2007 and February 2014 Tips of the Month (TOTM), we studied in detail the water phase behaviors of sweet and sour natural gases and acid gas systems. We also evaluated the accuracy of different methods for estimating the water content of sour natural gas and acid gas systems. The waterContinue Reading