Prediction Technique

Drillstring drag is the cumulative force required to move the pipe up or down inside the hole. Torque is the movement required to rotate the pipe. Drag forces usually are paralleled to the string weight measured with the string rotating but not reciprocating. Measured from the rotating string weight, the pickup drag is usually vaguely greater than the slack-off drag. The magnitudes of torque and drag are related in any particular well; high drag forces and excessive torque loads usually occur together. There are various causes for excessive torque and drag, such as tight hole conditions, keyseats, differential sticking, sloughing hole, sliding wellbore friction and cuttings buildup caused by poor hole cleaning.

With the exception of sliding friction, these causes are associated with problem conditions in the wellbore. Contrarily, in wells with great hole conditions, the primary source of torque and drag is sliding friction. Torque and drag from any source tend to be more troublesome in extended-reach directional wells. In very deep, highly deviated wells, overcoming torque and drag can be vital to the successful well completion. The capability to predict frictional loads on drillpipe has two main benefits:

  1. Deep, highly deviated wells can be planned to minimize torque and drag and ensure successful drilling operations to total depth.
  2. A more complete knowledge of drillstring loading allows use of improved drillstring design techniques, having considered the extra forces involved.

Both torque and drag are assumed to be caused entirely by sliding friction forces that result from contact of the drillstring with the wellbore. Two factors affect sliding wellbore friction:

  1. The normal contact force
  2. The coefficient of friction between the contact surfaces

The product of these two factors represents the magnitude of the sliding friction force. The normal contact force between the pipe and hole wall depends on several factors such as, the effects of gravity on the pipe, the effects of tension acting through curvatures in the wellbore and even pipe bending. The sliding friction coefficient is the ratio of the friction force to the normal contact force. This factor depends on specific contacting materials and on the degree of lubrication at various places in the wellbore. However, the oil and gas industry has made many advancements technologically speaking and quite a few models have been developed for these kind of issues.

PVI’s torque and drag model, TADPRO, is designed to help remove many of the risks of a drilling program, completions design or specific tool operations. Limits in the length of a horizontal based on specific friction factors can be determined. It can evaluate the needed weight to a liner-top packer. TADPRO can analyze forces downhole and predict rig equipment specifications for torque and hookload. The model provides both versatility and accuracy in its calculations and it integrates advanced features that make it easier for our users to use.TADPRO - Torque and Drag Drilling Software

The Value of Teamwork

An organizational value is a belief that a specific mode of conduct is preferable to an opposite or contrary mode of conduct. We can think of these values as representing structures for the way we do things. Some organizations think of their values as their “guiding beacon” which directs the process of their organizational development and growth. Other companies describe them as the components of their work philosophy. Core values relate to how companies deal with their beliefs about their employees, customers and work. The studies regarding this subject show that successful companies place a great deal of emphasis on their values.

Values at work assist us by:

  • Providing a structure for how we treat one another at work.
  • Providing a structure for how we treat our customers.
  • Providing a structure for achieving the vision and increasing the effectiveness of the organization.
  • Creating an environment that leads to job satisfaction as well as finding work which is exciting and challenging.

Values at work are very important because:

  • They give us guidelines for our behavior even when we are stressed out.
  • It is a highly competitive world and they help us to show our customers how we are different from other providers.
  • People are aware of organizational values and look for them when choosing one company over another.
  • They provide the basis for achieving great change.
  • They help enable people and organizations to succeed.
  • They have an impact on professional practices.
  • They can provide a measurement of success for all employees.

WHAT OUR VALUES LOOK LIKE

Communication

Listening to and respecting each other achieves mutually beneficial results. When we are unsure we check with others as to what they meant. Everyone has strengths which we value and will use whenever possible. We request for help when needed.

Support

By providing support to one another, working co-operatively, respecting one another’s views and making our work environment fun and enjoyable, we help others to achieve their deadlines. We work with one another with enthusiasm and appreciation.

We work with one another without manipulation. Conflicts are resolved according to agreed guidelines for the team and they are brought out into the open and dealt with constructively until everyone is satisfied with the results.

Attitude

This requires being open and honest in all our dealings and maintaining the highest integrity at all times. All concerns are given with positive solutions offered. A good attitude is a skill everyone should learn to achieve.

Efficiency

Always doing what we say we will and striving for efficiency and quality in everything we do. Quality will always delight the client and keep everyone else in the company happy. We work efficiently toward a better future for the company.

Responsibility

Being responsible and committed helps the company to get successful perspectives and results both individually and collectively. Taking ownership of our customers’ needs and being accountable for delivering friendly and professional service. We are each fully accountable for our work in gaining any possible repeat business with customers.

Balance

We value learning, feedback, coaching and mentoring. Coaching and mentoring are commonplace in our company because we all coach and mentor one another. We see all opportunities as a learning experience and we pursue them. We have a balance between our personal life and our professional life and we try to keep a healthy work balance that helps us perform more efficiently. PVI Core Values

7 Basic Ideas

In completion of oil and gas wells, cement separates the wellbore, prevents casing failure, and keeps wellbore fluids from contaminating freshwaters. The basic factors engineers and operators must consider for successful cementing jobs are summarized in seven basic ideas:

  1. Condition the Drilling Fluid
  2. Use Centralizers
  3. Move the Pipe
  4. Increase the Displacement Rate
  5. Design Slurries for Proper Temperature
  6. Select and Test Cement Components
  7. Select a Proper Cementing System

1. Condition the Drilling Fluid

The drilling fluid condition is the most important variable in achieving very good displacement during a cementing job. As the workers pull the drill pipe, run the casing, and prepare for cementing operations, the drilling fluid in the wellbore basically remains static and hardens. Pockets of mud commonly exist after a wellbore is drilled and they make displacement difficult. These pockets of gelled fluid must be broken up. Regaining and maintaining good fluid mobility after running the casing is essential.

2. Use Centralizers

Centralizers are effective mud displacement helpers. Centralizers make easier the removal of gelled-mud and allow better cement bond with the wellbore. Centralizers are designed to serve various needs, for instance, they help with well control, provide increased mud-removal benefits, optimize drilling-fluid displacement. When a casing is poorly centralized the cement bypasses drilling fluid by following the path of least resistance. Good pipe standoff helps ensure uniform flow patterns around the casing. Centralizers also change fluid flow patterns and promote better mud displacement and removal.

3. Move the Pipe

Moving the casing before and during cementing breaks up the gelled pockets and it loosens the cuttings trapped in the gelled mud. Pipe movement allows high displacement efficiency at lower pump rates by keeping the drilling fluid flowing.

Movement compensates partially for poorly centralized casing by changing the flow path and allowing the slurries to circulate completely around the pipe. In some instances, some liner hangers and mechanical devices prevent casing movement, which must be considered during the cement displacement design.

4. Increase the Displacement Rate

High-energy flow in the annulus is more effective in ensuring good mud displacement. Turbulent flow around the casing circumference is desirable, but not necessarily essential. The best cementing results are obtained when the spacers and cement are pumped at maximum energy, the spacer is appropriately designed to remove the mud, and a more proficient cement is used.

5. Design Slurries for Proper temperature

Operators can optimize the slurry design if they know the actual temperature the cement will encounter. Bottomhole cementing temperatures affect the slurry thickening time, set time, rheology and the compressive-strength development. Operators tend to overestimate the amount of materials required to keep cement in a flowing for pumping, which can result in unnecessary cost and well-control problems. They can optimize cost and displacement efficiency by designing the job on the basis of actual wellbore circulating temperatures, obtained from a downhole temperature sub recorder.

6. Select and Test Cement components

Operators are encouraged to design cement slurries for specific applications, with good properties to allow placement in a normal period of time. The ideal cement slurries have no measurable free water, provide adequate fluid-loss control, have adequate retarder to ensure proper placement, and maintain a stable density to ensure hydrostatic control.

Before performing the job, they should check the cement reaction and actual location mix water to ensure that the formulation will perform as it is expected. Contaminants in the mix water can produce large variances in thickening time and compressive strength.

Organic materials and dissolved salts in mix water can affect the slurries setting time.

Cement dehydration from the loss of filtrate to permeable formations can cause bridging and increased friction pressure, viscosity, and density. Pump pressures can increase and additives can be used to provide fluid-loss control when is necessary to compensate for dehydration.

7. Select a Proper Cementing System

Operators select cement systems based on job objectives and well requirements.

Cement is basically inflexible. Cementing systems are similar in many ways, but sometimes they vary, for instance, in their capability to provide good zone isolation in changing environments. The cement selection has always been on the basis that higher compressive strengths result in higher cement sheath quality. Research has proven that the ability of cement to provide good zonal isolation is better defined by other mechanical properties. Good isolation does not necessarily require high compressive strength. The real competence test is whether the cement system in place can provide zone isolation for the life of the well.

For all these situations PVI has developed a series of software such as:

CentraDesign - Centralizer Placement Software

CentraDesign - Centralizer Placement Software

MUDPRO - Drilling Mud Reporting Software

MUDPRO - Drilling Mud Reporting Software

StuckPipePro - Stuck Pipe Analysis Software

StuckPipePro - Stuck Pipe Analysis Software

that can help engineers and operators to perform a better quality job and avoid any potential problems that can put at risk the production.

A New Drilling Engineering Toolbox App

Every drilling engineer and technician knows that performing drilling engineering calculations can be a tedious and time-consuming process, considering the many researches they have to do in order to find the right results. At times, even these results are not quite exact. While technology has tremendously driven the oil and gas industry forward with the creation and development of advanced software, most of the time these are meant to be used in the office and are not so simple and portable. To assist with this issue, Pegasus Vertex, Inc. has launched the new DR.DE Lite mobile app for both Android and Apple devices. This free app was developed to provide drilling engineers and technicians with a simple, useful, paperless and portable tool to make their drilling engineering calculations easier and faster.

Dr.DE_Lite_Mobile_AppThe DR.DE Lite app is equipped with 29 functions that are divided into 11 groups.

Dr.DE Lite App: 11 GroupsFrom this great selection of functions, this tool can help you save time and efforts to get the calculations you need. In the past, drilling engineers and technicians had to obtain the information from different sources and after gathering the information manually perform the calculations and that could take up to an hour; however, now it can be done in a matter of seconds and the results are precise.

In this new tool, every function comes with three main buttons: Default, Clear and Calculate. The “Default” button gives users an example of standard input data. The “Clear” button allows users to delete all input data and the “Calculate” button performs the calculations based on the data users enter. The app collects all the information the users provide and in case the wrong data is entered, it will give a message as a warning.

For example, the “Hydraulic’ group contains four sub-functions: 1. ECD, which calculates the ECD at depth. 2. Hydrostatic pressure, which calculates the hydrostatic pressure of the mud column in a deviated well. 3. Pressure drop (Bingham) annulus, which calculates the pressure drop in an annular section for Bingham plastic fluids. 4. Pressure drop (Power law) annulus, which calculates the pressure drop in an annular section for power-law fluids.

Dr.DE Lite: Pressure DropIn the “Pressure drop” function, users can specify the wellbore configuration, as well as fluid properties and flow rates. DR.DE Lite performs calculations for fluid velocity, flow pattern, pressure drop, Reynolds number and other key parameters for different flow patterns.

The DR.DE Lite app is the perfect tool that complements your work. It’s easy to download, easy to use, very convenient and free. To download DR.DE Lite, scan the QR code or download the app from your mobile play store.

Dr.DE_Lite: Free Drilling Engineering Toolbox Mobile App