How to calculate Well Bore pressure drop?

[DAH7542]

Dear ibtisam01,

1. How can I calculate pressure drop along the well bore length
- There are plenty of papers on this. Start by reading Joshi's book on Horizontal Wells, from p. 398. Then take a look of these papers: SPE 19824, SPE 21124, SPE 36608, SPE 48937. Modelling the pressure drop through the horizontal section incorporates more information to the simulation model, however this issue can be ignored under some specific conditions such as: non-turbulent flow (flow rates less than 10,000 bpd according to the literature) and low viscosity fluid flows, take a look at SPE 24941. After this background, you'll be able to built your own spreadsheet of dP as function of horizontal well length (L).

2. How I can calculate reservoir draw down i.e. difference b/w average reservoir pressure and the pressure and the producing end(Heel) of the well bore.
- This can be done by using User Defined Quantities (UDQ) in E100. With this functionality of E100 any variable can be defined and reported as a part of the SUMMARY section. Simply use UDQ to defined drawdown as the wellblock pressure minus WBHP. You can then plot drawdown as a function of horizontal well length (L) to observe the pressure distribution within the horizontal section.

[ibtisam01]

Thanks for the valuable info. Well I have tried starting reading papers, but i have very less time available to complete my project. Now I ask you one question regarding calculation of pressure drop along the well bore length. I have 2 strategies coming in my mind.

1. If I minus WBHP from the connection pressure (at the toe of horizontal section) , will this be the pressure drop along the length of horizontal section?

2. If I minus connection pressure (at the heel of horizontal section) from the connection pressure (at the toe of horizontal section) , will this be the pressure drop along the length of horizontal section?

Kindly reply. Thanks in advance.

Dear ibtisam01,

1. How can I calculate pressure drop along the well bore length
- There are plenty of papers on this. Start by reading Joshi's book on Horizontal Wells, from p. 398. Then take a look of these papers: SPE 19824, SPE 21124, SPE 36608, SPE 48937. Modelling the pressure drop through the horizontal section incorporates more information to the simulation model, however this issue can be ignored under some specific conditions such as: non-turbulent flow (flow rates less than 10,000 bpd according to the literature) and low viscosity fluid flows, take a look at SPE 24941. After this background, you'll be able to built your own spreadsheet of dP as function of horizontal well length (L).

2. How I can calculate reservoir draw down i.e. difference b/w average reservoir pressure and the pressure and the producing end(Heel) of the well bore.
- This can be done by using User Defined Quantities (UDQ) in E100. With this functionality of E100 any variable can be defined and reported as a part of the SUMMARY section. Simply use UDQ to defined drawdown as the wellblock pressure minus WBHP. You can then plot drawdown as a function of horizontal well length (L) to observe the pressure distribution within the horizontal section.