WELL PERFORMANCE ANALYSIS In The Name of God P.O.G.C Subject of Conference WELL PERFORMANCE ANALYSIS

Outlines Introduction Inflow performance relationship (IPR) Tubing performance relationship (TPR) Wellhead performance relationship (WPR)

Goals of Well Analysis Determination of the flowrate To determine under what flow conditions well will cease to produce. To select the most economical time for the installation of artificial lift To optimize the well conditions and system geometry To analyze each component in the well system

production system Sales Gas surface facility Separator Stock tank vertical well porous media 5

Inflow Performance Relationship (IPR) Inflow performance relationship (IPR) is defined as the relation between the surface flowrate (q) and bottomhole flowing pressure (Pwf). IPR curves are used to analyze the deliverability of wells by estimating the production rate for a given bottomhole flowing pressure and vice versa and also reflect the ability of the reservoir to deliver fluid to the wellbore.

IPR Curve 1) Straight line (Constant PI) 2) A curve which shows that the PI is decreasing with rate 3) A combination of 1 and 2.

Constant PI Occurs for single phase liquid flow Production rate is proportional to the pressure drawdown

IPR Equation for Multiphase Flow Vogel’s Equation Fetkovich’s Equation Klins and Majcher Equation Pudjo Sukarno’s Equation

Fetkovich’s Equation Using data from multirate tests on 40 different oil wells in six fields, Fetkovich showed that the following approach was suitable for predicting performance: where 0.5 ≤ n ≤ 1.0 Log This can be expressed in a form similar to Vogel’s IPR. (Pr2 – Pwf2) psia 1/n Flowrate ( q ) STB/d Log

IPR Curve for Multiphase Flow

Effective Parameters on Inflow Performance Dow point and bubble point pressure Reservoir pressure depletion Skin effect

Tubing Performance Relationship (TPR or VFP) Tubing performance may be defined as the behavior of a well in giving up the reservoir fluids to the surface. relation between the surface flowrate (q) and tubing intake ressure(Pwf). Flowing bottomhole pressure (tubing intake pressure) for each production rate equals total pressure drop through the tubing and any bottomhole restriction and wellhead pressure. Pwh Pwf Q

Pressure Drop In the Vertical Well Hydrostatic pressure drop Friction pressure drop

Vertical Two-Phase Flow Pattern Bubble flow (A) Slug flow (B) Transition flow (C) Annular-mist flow (D)

Flow Regimes

Change in phase behavior in the production tubing

Natural flow Accrue when the wellbore flowing pressure and tubing intake pressure (at perforation depth) are equal, TPR and IPR curves intersect together. The intersection of TPR and IPR curves called natural flow point.

Variables that Effects on Natural Flow Wellhead pressure Gas/liquid ratio Tubing size Static pressure &…

Effect of Wellhead Pressure

Effect of Gas/Liquid Ratio

Effect of Tubing Diameter

Effect of the Skin

BHSP 5900 5500 5000 4500 4100

Wellhead Performance By using of the wellhead performance can show in which range of flowrate in the well column, the hydrostatic pressure drop is more than friction pressure drop.

production system Sales Gas Separator Stock tank vertical well porous media 26

IPR & TPR & WPR Pwh IPR Pressure TPR WPR Rate

Choke Performance The main function of a choke is to dissipate large amounts of potential energy (i.e., pressure losses) over a very short distance. Two types of two-phase flow can exist in a choke : P2/P1 ≤ %50 = RC Critical flow Subcritical flow P2/P1 > %50 = RC P1 = Wellhead ( upstream) pressure P2 = downstream pressure

CPR and WPR The intersection of the WPR and choke performance curve defines the rate of natural flow for the given choke size.

Gilbert and Ros

Recommend Basic requirement for well performance analysis is the ability to determine , so it is required to determine BHP using surface data Determine the best correlation to predict the fluid behavior in well column same as culender smite or duckler &… Examine the quality of separator tests using daly reports of SPGC

Thanks for your attention