Why is stress important in petroleum engineering?

Wellbore failure occurs because the stress around the well exceeds the strength of the rock.

In [2]:
from PIL import Image
import requests
import io
import IPython.display

url = 'http://petrowiki.org/images/thumb/b/b0/Devol2_1102final_Page_051_Image_0001.png/300px-Devol2_1102final_Page_051_Image_0001.png'
response = requests.get(url)
#Load image from url
img = Image.open(io.BytesIO(response.content))
#Crop original image
width, height = img.size
cropped = img.crop((0, 0, width, int(height-28)))
#resize image while maintaining aspect ratio
basewidth = 500
wpercent = (basewidth/float(width))
hsize = int((float(height)*float(wpercent)))
resized = cropped.resize((basewidth,hsize), Image.ANTIALIAS)
resized.save('images/wellbore.png')
IPython.display.Image('images/wellbore.png', embed=True)
Out[2]:

© American Geophysical Union, © Centek Publishing Image Source

Faults will slip when the ratio of shear to normal stress on the fault exceeds its frictional strength.

In [3]:
IPython.display.Image('images/slip.png', embed=True)
Out[3]:

© USGS Image Source

Reservior depletion causes changes in the stress state at depth that can be beneficial, or detrimental, to production.

In [4]:
url = 'http://iesl-global.com/wp-content/uploads/2014/06/ReservoirPressureIllustration.jpg'
response = requests.get(url)
#Load image from url
img = Image.open(io.BytesIO(response.content))
#Crop original image
width, height = img.size
cropped = img.crop((10, 150, int(width-10), int(height-10)))
#resize image while maintaining aspect ratio
basewidth = 500
wpercent = (basewidth/float(width))
hsize = int((float(height)*float(wpercent)))
resized = cropped.resize((basewidth,hsize), Image.ANTIALIAS)
resized.save('images/depletion.png')
IPython.display.Image('images/depletion.png', embed=True)
Out[4]:

© IESL Image Source