Important Mechanical Properties of Materials and Effect of Corrosion on Load Carrying Components

Mechanical properties of material are one of the most important basic concepts in a well design and this section will briefly discuss about key mechanical properties and their applications. Furthermore, there is a discussion about effect of corrosion on the mechanical performance of load carrying components.


Mechanical Properties of Material

Basic mechanical properties are as follows;


Hardness is a resistance of materials to permanent deformation and is sometimes referred to a resistance to abrasion or scratching. The greater of the hardness, the harder it is for the materials to deform. The application of hardness is to inspect if materials have been properly treated during a heat treatment process. The comparison between the actual hardness and the standard hardness of materials will show whether the current batch of material is proper and suitable for use or not.


Strength of material is an ability to work within a load without failure of the material. Tensile and yield strength are critical properties in terms of material strength.

Tensile Strength

Tensile strength or ultimate tensile strength is the maximum stress on an engineering stress-strain curve. At this point, materials are plastically deformed but they may not be broken apart yet depending on types of materials. Continue reading

Tubular Material Selection for HTHP Well with Example Calculation

This article demonstrates how to select material that will be suitable for high pressure, high pressure and corrosive environment. The material chart is based on the Sumitomo tubular chart.


Well conditions are as follows;

Reservoir: High pressure & high temperature gas reservoir

Reservoir Temperature: 420 F (216 C)

CO2 content: 2.9% mol

H2S:40 ppm

Chloride Ion Content in Produced Water: 150,000 ppm

Fluid saturation pressure: 10,000 psig Continue reading

Important Material Properties of Tubular and Completion String

It is imperative to understand mechanical properties of tubular because it involves the safety structure of the well. Failure in completion can cause major catastrophic problems in people safety, major loss of expenditure and loss of production from a well.

This article will describe the basic mechanical properties which are very essential to understand. Continue reading

Determine Quantity of Material Used in Mixing a Simple Drilling Mud

This is a simple example to demonstrate how to determine quantity of material required in a simple mixing system. Let’s learn from the example below.

The objective is to build mud which has a weight of 11.0 ppg with 1,000 bbl.

The mud recipe is shown below;

  • 30 ppb bentonite
  • 5 ppb CMC polymer
  • 5 ppb caustic soda (NaOH)
  • 25 ppb Na2CO3
  • Weighting Material is barite.

The following are important data of water and chemical used for this calculation.

Base fluid = fresh water

Specific gravity of water = 1

Specific gravity of barite = 4.2

Specific gravity of bentonite = 2.4

Specific gravity of CMC polymer = 2.4

Fresh water weight = 8.34 ppg

NaOH and Na3CO3 have negligible volume because it is dissolvable.

What is quantity of material required to meet the mud specification?

What is the final volume? Continue reading

Material Balance for Gas Reservoir

For gas reservoirs, the material balance concept can be applied to determine gas in place and expected gas reservoir reserve.

Gas Production = Expansion of Free Gas In Reservoir

equation 1 Gp


  • Dry gas reservoir
  • No external energy support like water drive.


Gp = gas production (std cu-ft)

Bg = gas formation volume factor (res cu-ft/std cu-ft)

G = gas in place (std cu-ft)

Bgi = initial formation volume factor (res cu-ft/std cu-ft)

Gas formation volume factor (Bg)

equation2 bg Continue reading