Coring Cost Per Footage Drilled

Coring is a special process to recover wellbore rock in the well.

Figure 1 - Core from the well. Credit – Wikipedia
Figure 1 – Core from the well. Credit – Wikipedia

This article will demonstrate how to calculate coring cost per footage recovered.

coring-cost-per-foogate-drilled

 Coring cost per footage recovered is expressed below;

coring cost per foot formula

Where;

Cc = coring cost per foot

Cb = cost of core bit

Cs = cost of coring service from a service company

Cr = rig day rate

tt = trip time, hour

tc = core recovering time, hour

trc = core barrel handling time, hour

L = length of core recovered, ft

Rc = percentage of core recover, %

Example – Geologist plans to do coring from 14,000 – 14,500 ft. The information for this operation is listed below;

Coring bit = 20,000 $

Coring service price = 120,000 $

Rig day rate = 100,000 $

Expected trip in and out time = 24hours

Core recovery time = 12 hours

Core and tool handling time = 4 hours

Expected core recovery = 90 %

Determine the expected coring cost per foot.

 Figure 2 - Coring Depth

Figure 2 – Coring Depth

Solution

Cb = 20,000 $

Cs = 120,000 $

Cr = 100,000 $/day ( 4166.67 $/hr)

tt = 24 hrs

tc = 12 hrs

trc = 4 hrs

L = 500 (14,500 – 14,000)

Rc = 90 %

coring cost per foot formula-2

Cc =681.5 $/ft

Coring cost per footage drilled is 681.5 dollars.

Reference book => formulas-and-calculationFormulas and Calculations for Drilling Operations 

Tagged , . Bookmark the permalink.

About DrillingFormulas.Com

Working in the oil field and loving to share knowledge.

2 Responses to Coring Cost Per Footage Drilled

  1. Yousef Hasan says:

    Dear support team,

    Many thanks for the valuable website. I need your help in downloading some of your articles.
    I’ve tried times and times to download the following but no way:
    1- The red book of Haliburton.
    2- Well control Quiz.
    Your help is highly appreciated.

Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.