Fluid saturation is how much each fluid is present in pore spaces of a rock. This will affect the ability of each fluid flow through porous media. This is one of critical values for reservoir engineering since many engineering calculations need fluid saturation values.
Fluid Saturation in Rock
Fluid saturation is expressed in terms of volume of fluid divided by total pore space.
Gas saturation (Sg) = Vg ÷ Vp
Oil saturation (So) = Vo ÷ Vp
Water saturation (Sw) = Vw ÷ Vp Continue reading
When you learn about drilling mud, the rheological models are essential knowledge. The rheological models are critical for a drilling fluid study because they are used to simulate the characteristics of drilling mud under dynamic conditions. With this knowledge, you will be able to determine some of the key figures, such as equivalent circulating density, pressure drops in the system, and hole cleaning efficiency.
The drilling fluid has three flow regimes, plug flow, laminar flow and turbulent flow and Figure 1 demonstrates 3 flow regimes on the shear rate and shear stress curve. In between each zone, there is a transition zone where the flow regimes are changing.
Figure 1 – Various flow types Continue reading
Absolute permeability is an ability to flow fluid through a permeable rock when only one type of fluid is in the rock pore spaces. The absolute permeability is used to determine relative permeability of fluids flowing simultaneously in a reservoir.
Darcy’s equation is widely used in an oil field to measure flow in porous media and the Darcy’s linear flow equation is shown below;
Compressibility is a relative volume change of a fluid or solid in a response to a pressure change. We can relate this into a reservoir engineering aspect. Overburden pressure is rock weight and it typically has a gradient of 1 psi/ft. Rock metric and formation fluid in pore spaces supports the weight of rock above. When petroleum is produced from reservoir rocks, pressure of fluid in pore space decreases, but overburden is still the same. This will result in the reduction of bulk volume of rock and pore spaces. The reduction on volume in relation to pressure is called “pore volume compressibility (cf)” or “formation compressibility” and it can be mathematically expressed like this.
This page contains well control contents in this site.
Adjusted maximum allowable shut-in casing pressure
Brine weight with temperature correction
Calculate Annular Capacity
Calculate Annular Pressure Loss
Calculate Equivalent Circulation Density (ECD) with complex engineering equations
Calculate Influx Height
Calculate inner capacity of open hole/inside cylindrical objects
Calculate Pressure Gradient and Convert Pressure Gradient
Calculate Specific Gravity (SG) in oilfield unit
Convert Pressure into Equivalent Mud Weight
Convert specific gravity to mud weight (ppg and lb/ft3) and pressure gradient (psi/ft)
Corrected D Exponent Calculation
D Exponent Calculation
Determine height of light weight spot pill to balance formation pressure
Determine the actual gas migration rate
Drill pipe pulled to lose hydrostatic pressure
Equivalent Circulating Density (ECD) in ppg
Equivalent Circulating Density (ECD) Using Yield Point for MW less than 13 ppg
Equivalent Circulating Density (ECD) Using Yield Point for MW More than 13 ppg
Estimate gas migration rate in a shut in well
Estimate Type of Influx (kick)
Formation Integrity Test (FIT) Procedure and Calculation
Formation Pressure from Kick Analysis
How does the 0.052 constant come from?
Hydraulic Horse Power (HPP) Calculation
Hydrostatic Pressure (HP) Decrease When POOH
Hydrostatic Pressure Calculation
Hydrostatic Pressure Loss Due to Gas Cut Mud
Kick Tolerance Calculation
Kill Weight Mud
Leak Off Test (Procedures and Calcuation)
Loss of Hydrostatic Pressure due to Lost Return
Maximum pit gain from gas kick in water based mud
Maximum Surface Pressure from Gas Influx in Water Based Mud
Pipe Displacement Calculation
Pump Output Calculation for Duplex Pump and Triplex Pump
Pump pressure and pump stroke relationship
Temperature Conversion Formulas
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