A squeeze cementing method wherein the well tubing does not have to be pulled from the well so no workover rig is needed; a smaller volume of squeeze cement is required; the pressures involved in the squeeze operation can be precisely controlled with no risk of fracturing the formation; and there is no need for any drilling operations to remove hardened cement remaining in the well casing.

Today’s oil and gas investments are highly complex, risky and multidisciplinary ventures that require careful planning and precise implementation. Fundamental to the success of all project management is extensive economic modeling and risk analysis, since a large numbers of interrelated factors and unforeseen events (operational, technical and financial) determine a drilling, completion, or workover project’s economic feasibility and ultimate success.

One of the key factors that is affecting the economic model is the fiscal regimes. Fiscal regimes describes all legislative, taxation policy, contractual and fiscal elements under which operations are conducted in petroleum provinces.

PVT analysis of reservoir fluid samples provides essential information for determining hydrocarbon in place, depletion strategy, and hydrocarbon flowability. Hence, quality checking (QC) is necessary to ensure the best representative sample for further analysis.

Check more about PVT from A to Z here in the following course :

Introduction

The definition of Reservoir Rock Types (RRT) is a key element of permeability and saturation modelling in complex clastic reservoirs, where detailed characterization is required. A field case in Central Asia is hereby presented, where the main reservoir belongs to the Lower Cretaceous (Aptian), and is highly heterogeneous:  it is composed of stacked, thinly interbedded and partially amalgamated marine sandstones and heteroliths/shales forming tortuous and complex architectures.

Job Title: Sales Representative

Company: OPA Energy

Location: New Degla, Maadi-Cairo.

About Us: Founded in 2019 and headquartered in Egypt, with a strategic presence in Lebanon and Norway, OPA Energy is a leading provider of innovative AI solutions and training development in the Oil & Gas industry.Our global partnerships span across key markets, including Iraq, KSA, UAE, Libya and Yemen. Additionally, we proudly host the first e-platform in the MENA region dedicated to petroleum-related training and soft skills courses.

Recap of our participation in the PACE Conference 2024! We offered job opportunities, free vouchers for our E-Platform, and showcased our growth. Special thanks to Eng. Adel for his efforts! Stay tuned for more exciting updates!

Hydraulic fracturing simulation tools are instrumental in optimizing fracture designs, predicting production rates, and ensuring the safe and efficient extraction of hydrocarbons. The complexity of hydraulic fracture propagation, combined with data uncertainties, presents significant challenges. Hydraulic fracturing involves modeling the dynamic interaction between fracturing fluid—whose composition and characteristics evolve under varying pressure and temperature conditions—and the reservoir rock and fluids. These interactions typically extend to at least 300 feet from the wellbore, while the available data generally pertains to a range within approximately 10 feet of the wellbore.

Decline Curve Analysis (DCA)

DCA is an empirical technique that uses production rate data and time to estimate reserves.

Equation Used:

Arps Equations: An empirical equation that depends on:

• Initial rate (qi)
• Decline rate (Di)
• Curvature of the decline (b)

Formula:

q= qi / ( 1 + bDit)^1/b

Rate Transient Analysis (RTA)

RTA is a technique that uses production data, such as rate, pressure, and time, to estimate reserves and other parameters based on physical principles.

Equation Used:

Flowing Material Balance (FMB) Equation: Combines compressibility and Darcy's equations:

It is a combine of compressibility equation and Darcy one.

Formula:

(Pi - Pwf )/q= mpss * (Np /q)+ bpss

where:

mpss = 1/(ct * N)

bpss = 1 / Productivity index

Discover a wealth of knowledge and elevate your skills with our expertly curated reservoir webinars. Each session is designed to provide in-depth insights and practical knowledge from industry experts.

Normalization in data analysis is a technique used to adjust the values of numeric data in a dataset to a common scale. The primary goal is to ensure that the data is measured on the same scale, which can prevent bias and improve the accuracy and efficiency of the analysis.

One of its types is Min-Max Scaling: This method scales the data to a fixed range, usually 0 to 1, by subtracting the minimum value and dividing by the range of the data.

How Can We Measure the Heterogeneity of a Reservoir Effectively?

In reservoir engineering, understanding how uniform—or not—your reservoir is can significantly impact management and extraction strategies. Here are two critical methods to determine this:

• Lorenz coefficient
• Dykstra-Parsons

In the field of reservoir engineering, calculating permeability accurately is crucial. Various methods, such as logging techniques (NMR, Sonic, Resistivity, MDT/RFT) and coring methods, particularly rock typing, play significant roles.

Today, let's delve into Rock Typing:

Geological Facies Rock Typing

• Involves rocks with common lithology, grain size, and texture linked to the depositional environment.

Petrophysical Rock Typing

• Focuses on rocks with a Porosity-Permeability relationship.
• Hint: G&G and RE should agree on the same number of rock types.

Estimating Permeability From Sonic Log

An innovative permeability derivation method and workflow has been developed using the Stoneley wave attenuation mechanism. This method offers a more accurate and sensitive approach to estimating formation permeability. Here are the key aspects and details of the methodology and findings:

Basis of the Method:
- Stoneley-Wave Characteristics:
- The method is based on the relationship between Stoneley-wave propagation characteristics and formation permeability. Specifically, as formation permeability increases, Stoneley-wave velocity decreases while its attenuation increases.

Level Up Your Production Technology Knowledge with Our Expert Webinars!

We have an outstanding series of webinars designed to boost your skills and knowledge in production technology. Don't miss out on these insightful sessions led by industry experts!

Water Control Diagnostic Techniques

1. Log-Log Plots

- Plotting WOR and GOR on log-log scales reveals distinct trends, making it easier to diagnose production problems.
2. WOR Derivatives
- Analyzing the derivatives of WOR helps differentiate between water coning and multilayer channeling.
3. Numerical Simulations
- Systematic simulations support the development of these diagnostic plots, enhancing their accuracy and reliability.

1. Look at the directions of the curve deflections (whether to the right or to the left) in these following sequence: GR-Res-Density-Neutron.

1. Tight non-reservoir: Right-Right-Right-Right.

GR-Res-Density-Neutron all deflect to the right.

Why it works: If we are not in a reservoir zone, GR is higher due to larger natural radioactivity from U, Th, K contents. Resistivity is higher due to tightness. Density and Neutron read low porosity.

Classification of porosity?

1. Primary porosity: the main or original porosity system in a rock or unconfined alluvial deposit.

2. Secondary porosity: A subsequent or separate porosity system in a rock, often enhancing the overall porosity of a rock. This can be a result of the chemical leaching of minerals or the generation of a fracture system. This can replace the primary porosity or coexist with it.

3. Effective porosity (also called open porosity): Refers to the fraction of the total volume in which fluid flow is effectively taking place and includes catenary and dead-end (as these pores cannot be flushed, but they can cause fluid movement by release of pressure like gas expansion[3]) pores and excludes closed pores (or non-connected cavities). This is very important for groundwater and petroleum flow, as well as for solute transport.

Permeability and Its Types

1. Absolute Permeability: This defines a material's capacity to allow a single, non-reactive fluid to pass through. It is a critical concept in hydrogeology and petroleum engineering for assessing fluid movement in subsurface formations.
2. Effective Permeability: This measures how efficiently a fluid moves through a porous medium that is already saturated with other fluids. For example, in a reservoir containing both oil and water, the permeability for each fluid will differ based on their interactions within the medium.
3. Relative Permeability: This compares the permeability of a material to one fluid relative to another, typically in situations involving multiphase flows, such as oil, water, and gas in reservoirs.

Thermal Flooding in Enhanced Oil Recovery (EOR)

Thermal flooding is a key method in Enhanced Oil Recovery (EOR) used to extract crude oil that can’t be recovered by conventional methods. By reducing oil viscosity through heat, it improves oil flow and extraction. Here’s a look at the primary techniques:

• Hot Fluid Injection: Involves injecting steam or hot water into the reservoir. This method reduces oil viscosity, improving flow.

1. Cyclic Steam Stimulation (CSS): Steam is injected, the well is closed to soak, then oil is produced from the same well.
2. Steam Flooding: Steam is injected continuously into one well, with oil being produced from surrounding wells.
3. Steam-Assisted Gravity Drainage (SAGD): Uses two horizontal wells to inject steam and collect oil, taking advantage of gravity.

• In-Situ Combustion (ISC): Oil is ignited in the reservoir to create heat, which pushes the remaining oil towards the production wells.

1. Dry Forward Combustion: Air is injected to burn the oil and push lighter oil forward.
2. Wet Forward Combustion: Water is injected with air to retain more heat and make the process more efficient.

The Evolution of Resistivity Logging in Subsurface Exploration

The Theory Behind Resistivity Logging

Resistivity logging measures the electrical resistance of rock formations to infer their properties. By introducing electrical currents into the subsurface and measuring the response, we can determine:

• Porosity and Permeability: How porous a rock is and how easily fluids can flow through it.
• Fluid Content: Differentiating between oil, gas, and water-bearing formations.
• Lithology: Identifying rock types based on their resistivity signatures.

Water Influx in Reservoirs

Water influx, also known as water encroachment, plays a vital role in maintaining reservoir pressure and influencing production performance. It occurs as surrounding aquifers respond to pressure differentials caused by fluid production from hydrocarbon reservoirs.

Water Influx: A Deep Dive into Mathematical Models

• Explore mathematical water influx models—essential tools for predicting water movement in reservoirs and optimizing petroleum extraction.

• Delve into widely used models like Pot Aquifer, Schilthuis' Steady-State, Van Everdingen-Hurst Unsteady-State, and more, and learn how they are applied in water influx calculations.

Read the Pdf file attached below.

Log Quality Control (LQC)

Log Quality Control (LQC) is essential for ensuring that well logs are accurate and reliable. Incorrect logs can lead to erroneous interpretations, making it critical to identify and correct errors early.

Objectives of LQC

• Understand how to read field logs/prints.
• Learn how to perform LQC.
• Prevent wrong interpretations caused by errors in raw logs.

LQC is conducted in two steps:

1. At the Wellsite (Field Engineer)
2. At the Office (Log Analyst)

Understanding tool physics and the environment allows errors in logs to be corrected before final analysis.

Water flooding is a vital enhanced oil recovery technique aimed at maximizing crude oil extraction. The first step in designing a water flooding project is selecting the appropriate flood pattern to ensure optimal contact between the injection fluid and the crude oil system.

Flood Pattern Selection

The objective is to choose a pattern that allows the injection fluid to maximize contact with the oil. This can be achieved by:

1. Converting Existing Production Wells: Turning some production wells into injection wells.
2. Drilling Infill Injection Wells: Adding new wells to enhance fluid distribution.

The suitability of the flooding pattern depends on the number and location of existing wells in the reservoir.

Factors Influencing Flood Pattern Selection

When selecting a flooding pattern, consider the following factors:

1. Reservoir Heterogeneity: Variations in rock properties and composition.
2. Directional Permeability: Flow characteristics that affect fluid movement.
3. Direction of Formation Fractures: Orientation can significantly impact flow patterns.
4. Availability of Injection Fluid: The type of fluid available (gas or water).
5. Desired and Anticipated Flood Life: Longevity of the flooding p

Density logs are primarily used as porosity logs. Other uses include:

• Mineral Identification in Evaporite Deposits
• Gas Detection
• Hydrocarbon Density Determination
• Evaluation of Shaly Sands and Complex Lithologies
• Oil-Shale Yield Estimation
• Overburden Pressure Calculation
• Assessment of Rock Mechanical Properties

Gamma Ray Interactions in Density Logging

Gamma rays emitted during density logging interact with materials via three processes:

1. Pair Production (>3 MeV):
   • Interact with nuclei to produce an electron and a positron.
   • Low efficiency; minimal contribution to the

What is Artificial Lift (AL)?

Artificial lift is a method used to enhance the production of oil or gas when natural reservoir pressure is insufficient to push fluids to the surface.

Why use Artificial Lift?

• The well ceases to flow naturally.
• The well is not producing economically.

Types of Artificial Lift

1. Pumping Method:
   Uses mechanical motion to impart energy to fluids, lifting them to the surface.

2. Gas Lifting:
   Utilizes compressed gas energy to lift fluids to the surface.

Common Artificial Lift Techniques

• Gas Lift: Utilizes injected gas to lower fluid density, enabling efficient lifting in wells with adequate gas supply.
• Pumps:
  • Electric Submersible Pumps (ESP): Ideal for high-flow, deep wells requiring continuous electrical power.
  • Progressing Cavity Pumps (PCP): Perfect for handling viscous and abrasive fluids in challenging well conditions.
  • Sucker Rod Pumps (SRP): Traditional and reliable choice for shallow to medium-depth wells with moderate production.

Enhanced Oil Recovery (EOR)

Enhanced oil recovery (EOR), also known as Tertiary Recovery, is a crucial process used to extract additional oil from reservoirs after primary and secondary recovery techniques. It involves advanced methods to increase reservoir pressure or improve oil mobility for better extraction.

Theory

The Litho-Density Log is an improved version of the Formation Density Compensated (FDC) log. It measures both bulk density (ρb) and the photoelectric absorption index (Pe). While ρb primarily responds to porosity, Pe is mainly influenced by the rock matrix (lithology), making it valuable for identifying lithology.

The tool resembles the FDC log, featuring a pad containing a gamma-ray source and two detectors, pressed against the borehole wall by a backup arm. Gamma rays emitted at 662 keV scatter in the formation, losing energy until absorbed via the photoelectric effect.

At the far detector, the energy spectrum shows two regions (see Figure 1):

• Compton Scattering Region: Higher energy gamma rays inversely related to electron density.
• Photoelectric Effect Region: Lower energy gamma rays inversely related to both electron density and photoelectric absorption.

Surfactant Flooding

• Explore the various recovery methods and dive into the fascinating mechanism of surfactant flooding to maximize oil extraction.

• Learn about different types of surfactants, microemulsions, and how their phase behavior impacts interfacial tension (IFT) for effective EOR applications. Discover the methods to characterize surfactants and boost your understanding of this vital process.

Theory Behind Neutron Logging

In neutron logging, three processes are essential:

1. Neutron Emission:

   • Neutron tools emit high-energy (4.5 MeV) neutrons from a radioactive source comprising an alpha emitter (e.g., radium, plutonium, or americium) and beryllium-9.
   • Alpha particles interact with beryllium-9, producing carbon-12, fast neutrons, and gamma rays.

2. Neutron Scattering:

   • Fast neutrons undergo elastic scattering with atomic nuclei, losing energy and slowing down.
   • Energy loss is most efficient when colliding with nuclei of similar mass, notably hydrogen.
   • Neutrons slow from fast (>0.5 MeV) to thermal energies (

   Energy loss per collision depends on the target nucleus's relative mass and the scattering cross section.

   Efficiency of hydrogen, silicon, and oxygen atoms in slowing down fast neutrons in a clean sandstone (φ = 0.15).

Well stimulation is a specialized intervention performed on oil or gas wells to boost production. By improving the flow of hydrocarbons from the drainage area into the wellbore, stimulation techniques enhance the overall efficiency and output of the well. This process typically involves extending perforation tunnels and creating fractures within the reservoir rock to facilitate better hydrocarbon movement.

Types of Well Stimulation Techniques

There are primarily two types of well stimulation techniques:

1. Acidizing
2. Hydraulic Fracturing (Fracking)

1. Acidizing

Acidizing, also known as acid stimulation, involves using reactive acids to increase the permeability of the reservoir. This method dissolves acid-soluble solids naturally present in the rock matrix or those causing formation damage.

Types of Acidizing

Acidizing can be categorized into two main types:

• Matrix Acidizing
• Fracture Acidizing

Matrix Acidizing:

• Process: Acid is pumped into the formation below the fracture pressure.

Unlocking Reservoir Insights: Mastering Saturation Distribution and Modelling

• Dive into saturation distribution using capillary pressure (Pc) and repeat formation test (RFT) data—essential tools for understanding fluid behavior and distribution within your reservoir.

• Learn how to average capillary pressure using the Leverett J-Function to enhance reservoir characterization and predict fluid flow more accurately.

• Understand saturation height modeling and uncover trends in resistivity logs to optimize reservoir management and improve hydrocarbon recovery.

What For?

The main objectives of RFT (Reservoir Flow Test) and MDT (Modular Dynamic Testing) are to measure reservoir pressure, assess mobility, and determine the fluid content at specific reservoir intervals.

When Do We Need It?

RFT and MDT are beneficial during both the exploration and development phases of a reservoir. These tests are primarily performed in open hole using a cable-operated formation tester and sampling tool after determining the appropriate depth from logs. They are commonly conducted following petrophysical analysis results and serve as a quick and inexpensive alternative to DST (Drill Stem Test) tests.

Objectives of RFT/MDT

These pressure measurements are essential for:

• Variation in Pressure Among Formations: Identifying pressure differences between various geological formations.
• Fluid Pressure Gradient: Determining fluid pressure gradients within a formation to indicate fluid contacts.
• Fluid Contacts Identification: Locating gas-oil or oil-water contacts.
• Formation Permeability: Assessing the permeability of the formation.
• Controlled Local Production: Managing controlled local production and vertical interference.

Hydraulic Pumping Systems transmit power downhole using pressurized power fluid flowing through wellbore tubulars. A Jet Pump converts this pressurized fluid into a high-velocity jet that mixes directly with well fluids. Hydraulic piston pumps can lift large liquid volumes from great depths at relatively low pressures and handle crooked wells with ease. They can be powered by natural gas or electricity and are suitable for multiple completions and offshore operations. However, they have major drawbacks, including being fire hazards, costly power and water treatment, and issues with high solids production.

Applications for Hydraulic Pumping

Hydraulic systems are typically used where other artificial lift methods fail or are unsuitable due to well conditions. Despite being labeled expensive, they are ideal in scenarios where alternatives are not feasible:

1. Remote Areas: Hydraulic free pumps are ideal where rig costs are high or workover rigs are scarce.
2. Crooked or Deviated Wells: Efficiently handle non-vertical well paths.
3. Deep, Hot, High-Volume Wells: Suitable for wells with up to a 24° buildup per 100 ft.
4. Sandy Corrosive Wells: Jet pumps perform well in abrasive environments.

Enhance Your Drilling Knowledge with Our Rig & Rigless Operations Webinars!

We have a series of webinars tailored to boost your expertise in rig and rigless operations. Don't miss these insightful sessions led by industry experts!

Hydraulic fracturing is a stimulation technique where specially engineered fluids are pumped at high pressure and rate into the reservoir interval. This process causes a vertical fracture to open, with the wings of the fracture extending outward in opposing directions, guided by the natural stresses within the formation.

Key Components of Hydraulic Fracturing:

• Treatment Fluids: High-pressure fluids create fractures in the rock formation.
• Proppants: Typically grains of sand of specific sizes, mixed with the treatment fluid to keep fractures open post-treatment.
• High-Conductivity Communication: Ensures extensive contact with the formation, bypassing any near-wellbore damage to maximize hydrocarbon flow.

Why Hydraulic Fracturing?

Hydraulic fracturing offers several critical advantages:

• Increased Contact Area: Expands the well’s contact with the reservoir, enhancing hydrocarbon extraction.
• Bypassing Formation Damage: Overcomes damage near the wellbore, ensuring smoother flow paths for hydrocarbons.

What is Sucker Rod?

Sucker rod pumping, also known as Beam Pumping, mechanically lifts oil from the bottom hole to the surface. It is efficient, simple, and easy for field personnel to operate.

SR Pump Equipment

Surface Equipment Includes:

• Prime Mover: Drives the system, typically an electric motor or gas engine.
• Gear Reducer/Gearbox: Reduces the prime mover's speed and increases torque.
• Pumping Unit: Converts rotary motion to reciprocating motion using a walking beam.
• Polished Rod: Connects the walking beam to the sucker-rod string, sealing the wellhead.
• Wellhead Assembly: Contains a stuffing box for sealing and a pumping tee to direct fluids into the flowline via a check valve.

Downhole Equipment Includes:

• Rod String: Sucker rods inside the tubing link the surface drive to the subsurface pump.
• Pump Plunger: Moves with the rod string, featuring a traveling valve that lifts liquid on the upstroke.
• Pump Barrel (Working Barrel): The stationary cylinder with a standing valve for fluid entry during the upstroke.

Fundamentals of Well Testing

• Delve into constant rate testing, flow regimes, and superposition—vital concepts for interpreting well pressure data and fluid flow.

• Explore the impact of gas considerations and learn how to apply specialized plots like PITA to enhance your well test analysis and decision-making.

Progressive Cavity Pump (PCP)

A Progressive Cavity Pump (PCP) is a positive displacement pump that utilizes an eccentrically rotating single helical rotor turning inside a stator. This design allows PCPs to efficiently lift heavy oils at variable flow rates. PCPs are highly effective in handling viscous fluids and can operate reliably in challenging well conditions.

PCP Components

• Surface Drive:
  • Function: Supplies rotation and torque to the downhole PCP by suspending and rotating a drive string.
• Sucker Rod or Continuous Rod: Connects the pump to the surface drive system, transmitting mechanical energy.
• Progressing Cavity Pump:
  • Stator: Fixed to the tubing, providing the stationary cavity for the rotor to turn within.
  • Rotor: Attached to the rod string, it eccentrically rotates to create cavities that move the fluid upward.

Plunger Lift Principle

A Plunger Lift system uses a free piston that travels up and down within the well's tubing string. This mechanism minimizes liquid fallback and utilizes the well's energy more efficiently than slug or bubble flow methods. By removing liquids from the wellbore, the system allows the well to produce at the lowest possible bottom-hole pressures. The mechanics are consistent across oil, gas, and gas lift wells:

• Plunger Function: A steel plunger is dropped down the tubing to the well's bottom and travels back to the surface, acting as a piston between liquids and gas in the wellbore to prevent liquid fallback.
• Energy Utilization: The plunger creates a seal that leverages the well’s own energy to lift liquids efficiently, reducing the need for high gas velocities.

What is Acidizing?

Acidizing, also known as acid stimulation, involves injecting reactive acids into the reservoir to dissolve acid-soluble minerals and contaminants. This process increases the permeability of the rock formation, allowing for a more efficient flow of oil and gas to the wellbore. Acidizing is particularly effective in removing formation damage and enhancing the connectivity between the reservoir and the well.

Types of Acidizing

Acidizing treatments are broadly classified into three categories:

1. Matrix Acidizing
2. Fracture Acidizing
3. Spotting

Principle of ESP

ESPs operate by connecting an electric motor directly to a centrifugal pump module. The electric motor shaft is directly linked to the pump shaft, causing the pump to rotate at the same speed as the motor. This direct connection ensures efficient energy transfer and consistent pumping performance.

ESP Components

i) Subsurface Components:

• Pump: The main component that moves fluids to the surface. The pump is a multi-staged centrifugal pump. Each stage consists of a rotating impeller and a stationary diffuser. The type of stage used determines the volume of the fluid to be produced.
• Motor: Drives the pump, typically an electric motor.
• Seal Electric Cable: Protects the electrical connections from well fluids.

What is Gas Well Liquid Loading?

Gas well liquid loading refers to the accumulation of fluids within the tubing of a gas well. This phenomenon occurs when the gas flow rate becomes insufficient to overcome the force of gravity, leading to a buildup of liquids that can impede or halt production.

When Does Gas Well Liquid Loading Begin?

Liquid loading in gas wells begins when the gas flow rate is insufficient to overcome gravity. The critical point is reached when the gas flow rate and gravity forces are equal, resulting in the onset of liquid accumulation within the well.

Consequences of Liquid Loading

• Cessation of Production: Once the hydrostatic head equals the reservoir pressure, gas production stops.