Slide 1: Study the impact of improper choke design on gas production profile
Study the impact of improper choke design on gas production profile Sep-2019
Slide 2: Field General Overview
Field General Overview § Nidoco Offshore gas filed discovered and operated by ENI Egypt, • Gas Discovered at Jul-2015 • Production start up Aug-2015 • Reach Max plateau Nov-2017 (1150 MMSCF/D) • Offshore field drilled from onshore location with deviation wells. • Total Number of wells 14 wells • Pro
Slide 3: Case study
Case study § Normal workflow • Nidoco Offshore field drilled from onshore location with deviation wells up to ~ 4000 Mt depth • The production profiles were generated initially using 3D model approach with generic constrains such as ; – Plant capacity. – Arrival pressures. – Well deliverability and
Slide 4: Objective
Objective § Study the impact of improper designed elements on the production forecast, X 1. Surface elements (Orifice & Choke) ? • The production profiles forecast assumed that there is no pressure drop in the X-Tree valves. • The pressure drop across the any surface elements is a function of gas ra
Slide 5: Updated Workflow
Updated Workflow Action Tool 1- Update the history match and generate production forecast using generic constrain with current wells rate as control Eclipse 2- Model the impact of surface elements (orifice & choke) Pipesim 3- Include the impact of surface elements (choke & orifice) in eclipse ( Netw
Slide 6: History Match
History Match ---- Gas rate ----- THP 6
Slide 7: History Match
History Match ---- Gas rate ----- THP 7
Slide 8: History Match
History Match ---- Gas rate ----- THP 8
Slide 9: Forecast Profile using generic Constrains
Forecast Profile using generic Constrains 1150 MMSCF/D plateau, Current gas rate of wells for production control • Applying normal workflow the failed can sustain the plateau of 1150 MMSCFD for one year 9
Slide 10: Surface restrictions (Choke & Orifice)
Surface restrictions (Choke & Orifice) Overview The gas phase pressure drop is given by Bernouilli's equation: 𝟐 𝟏 𝑸𝑮 ∆𝑷𝑮 ∝ 𝝆𝒏 𝑨𝒃𝒆𝒂𝒎 10
Slide 11: Pressure drop Across Choke & Orifice (Bars)
Surface restrictions (Choke & Orifice) Pressure drop match & pressure drop relations generations 2.5 inch choke size performance Well Upstream Mid stream Downstream Gas rate Bars Bars Bars MSmc/D 1 149.2 109.8 85.6 1.4 Pressure drop Across Choke & Orifice (Bars) 2 123.8 88.7 85.4 2.68 3 115.9 85.3 2
Slide 12: Surface restrictions (Choke & Orifice)
Surface restrictions (Choke & Orifice) Implement the surface elements to 3D model § Generate VLP curves for each element in the surface components § Build network model as descried below to integrate the VLP with the 3D model results GRUPTREE PLANT FIELD / M_MASTER PLANT / Eclipse NX2_FL M_MASTER /
Slide 13: Impact of surface elements on Nidoco profile
Impact of surface elements on Nidoco profile • The surface elements have a significant impact on the production drop BC Surface elements (Orifice & Choke) 13
Slide 14: Impact of surface elements (Choke & Orifice) well by well
Impact of surface elements (Choke & Orifice) well by well ---- Gas production rate Minor impact because it has lower THP 14 - - - - Surface elements (choke & orifice) ـــــــــــBC
Slide 15: Impact of surface elements (Choke & Orifice) well by well
Impact of surface elements (Choke & Orifice) well by well Cont. ---- Gas production rate 15 - - - - Surface elements (choke & orifice) ـــــــــــBC
Slide 16: Surface restrictions (Choke only)
Surface restrictions (Choke only) Implement the surface elements to 3D model § Study the impact of choke if the orifice is removed. • Remove the orifice from the system • Build network model as descried below GRUPTREE PLANT FIELD / M_MASTER PLANT / NX2_FL M_MASTER / NX2_OF NX2_FL / NX2_WH NX2_OF / M
Slide 17: Impact of current choke opening only on Field profile
Impact of current choke opening only on Field profile BC Choke only , No orifice 17
Slide 18: Impact of current choke position only
Impact of current choke position only Remove the orifice from the system ---- Gas production rate Well 6 • The current choke position has a significant impact. • If the choke is fully open so it is recommended to be upgraded . Well 9 • The current choke position has a significant impact. • If the ch
Slide 19: Impact of current choke position only
Impact of current choke position only Remove the orifice from the system ---- Gas production rate Well 3 • The current choke opening has a significant impact. • If the choke is fully open so it is recommended to be upgraded . Choke actions 1. Wells 3,6,9, and 10 current choke position will affect on
Slide 20: Conclusion
Conclusion § All orifice elements have a significant impact on Field profile. § 4 wells (3,6,9, and 10 current choke position will affect the production profile and need to be upgraded and revised) 1- BC (no bottleneck) 2- Surface elements constrain 3- Choke only constrain 20