Artificial Lift for Subsea Applications

The natural decline in the reservoir energy will impact the flowrate of oil, gas or water, thereby creating instabilities and resulting in decreased production. Artificial lift is used in oil-dominated or liquid-loaded gas systems to increase and stabilize hydrocarbon production, as well as to minimize flow assurance and operational risks, such as slugging in the subsea production system. Artificial lift methods transfer energy to the produced fluid with the objectives of reducing the fluid density and the pressure head or boosting the flowing pressure.

PWV Barrier Leak Test Acceptance Criteria Calculations

This GATEKEEPER discusses an effective subsea tree PWV (USV) leak test method. The test can be done quickly – entire test time is about 15 minutes, including the 5 minute monitoring time. More importantly, the test gives repeatable, unambiguous results that are easy to interpret and it can be done easily during any well shutdown. 

Acidizing Effects of Titanium Grade 29 Tapered Stress Joints

Titanium (Ti) alloys are attractive to subsea oil and gas operators due to their high strength, low density relative to steel, and innate corrosion resistance. The current primary application for Ti alloys has been in tapered stress joints (TSJs). Ti stress joints are a primary and sole barrier to loss of a riser and release of hydrocarbons into the environment. Therefore, the integrity of the TSJ is of utmost importance, and integrity loss of a TSJ carries a very high inherent risk.

Well Integrity: A Holistic Approach to Annulus Pressure Management for Subsea Wells

Well Integrity: A Holistic Approach to Annulus Pressure Management for Subsea Wells

Annulus Pressure Management refers to an engineered approach ensure that casing annulus pressures do not challenge the well’s integrity during the life of the well. The aim is to maintain the casing pressure within the well’s mechanical design limits at all times by controlling the ‘A’ annulus pressure. 

The ‘A’ annulus is the annular space between the production tubing and the first string of casing (i.e. production casing) as shown in Figure 1.  In subsea wells, the ‘A’ annulus is the only annulus that can be monitored and controlled.

Bacterial Monitoring & Remediation in Pipelines

Bacteria inhabit the vast majority of oilfield water systems. These may either be attached to the pipe wall (i.e. sessile bacteria) or free floating through the system (i.e. planktonic bacteria). Planktonic bacteria do not directly contribute to the microbiologically induced corrosion (MIC) of pipeline systems; however, planktonic bacteria can attach to the pipe wall under the right conditions, becoming sessile bacteria. Consequently, there is some value in monitoring planktonic bacteria activity in a pipeline, although it is substantially less beneficial than monitoring the sessile population activity.

Operational Marine Risk Management: Process Safety

Identification and management of marine process safety risk exposure is a key focus area on every offshore project. However, there are new and evolving threats that continue to challenge the offshore industry’s ability to deliver incident free projects. Simply stated, these threats are the dilution of skills and limited experience prevalent in a rapidly expanding industry.

Effective CMMS Database Development

A maintenance management system is a tool used for managing and controlling work, materials, and equipment throughout the oil and gas production chain, from offshore platforms to refineries and pumping stations. Many maintenance management systems are becoming computerized, allowing for a central storage location for the majority of the asset information and data. Computerization of the maintenance system allows users to have access from multiple locations and, if properly set up and maintained, provides an effective tool to track activity over the life of the asset. Computerization of the maintenance system also enables linking of the company’s document management system, warehouse inventory system, and procurement and logistics systems, to name just a few. This linking capability empowers the computerized maintenance management system (CMMS) to reach its full potential.

Riser Integrity Monitoring for HP/HT Wells

The increased use of dynamic risers as an enabling technology for the movement of the oil and gas industry into the deepwater basins of the world has presented new technical challenges related to the prevention of corrosion failures and other forms of degradation. This has been particularly evident when considering production from the next generation of high pressure/ high temperature (HP/HT) subsea developments in locations such as the Lower Tertiary trend in the Gulf of Mexico. In order to avoid potential riser failures or replacement campaigns for anticipated service lives that may extend to 30 years or more, process facility components such as risers and flowline systems must now be subjected to more enhanced integrity monitoring through the whole of their service life.

What’s Wrong With HAZOPs & What We Can Do About It

A HAZOP is a team-based process hazard analysis (PHA) method. Its purpose is to identify hazards and operability issues in a process design. HAZOPs are not fun! Maybe that's not a problem, but they also don't achieve what they could and that is a problem.

Why Don't We Learn What We Should From HAZOPs?

 HAZOPs are not as effective as they should be for several reasons, including:

  • Tunnel Vision - The focus on small nodes obscures the big picture.   
  • Guideword Excess - Flow, pressure, temperature, and level are not independent.
  • HAZOPs are supposed to identify operability issues, but they really don't explicitly address operability.
  • Risk assessment in HAZOPs is typically difficult, ambiguous and not repeatable.
  • HAZOP reports are difficult to read and are of limited use.
  • Most people don't enjoy HAZOPs and that impacts participation.

The GATE Stream-based HAZOP process avoids these pitfalls via some novel modifications to the process.

Evaluating Scaling Risks – What is the Big Picture?

Scale management, and the modeling and risk assessments that support it at the design stage of a project, is a critical part of the field development process for deepwater oil and gas developments. In many cases,  scaling risk assessments are undertaken very early in the appraisal and concept selection process and with minimal supporting data; however, the implications of such studies can drive field design and affect the commercial viability of a project.

Introduction to Risers

Utilized in a number of configurations, a riser presents the operator with a conduit that serves as the main method of hydrocarbon transport from the ocean floor to the host facility as well as a method of external media introduction such as chemical and water injection. Considering the large number of applications that risers have, as well as the dynamic environment  associated with subsea oil and gas exploration, it comes as no surprise that the down selection of various riser designs can be a complex process requiring extensive knowledge of each riser style. To aid in this design process, a number of standards have been developed to ensure safe practices throughout design and installation. Such standards and recommended practices can be seen in API RP 2RD, API RP 1111, ASME B31.4 and ASME B31.8 which should be utilized to keep safety at the forefront of the design.

Black Sea: Offshore Challenges & Solutions

Unlike most offshore oil plays, the Black Sea provides an unique array of environmental conditions. These features include an anoxic environment below 200 meters, high concentrations of sulfate reducing bacteria (SRBs), methane vents, and geological instabilities. These conditions create diverse challenges to subsea equipment and pipelines that are unique within the offshore oil and gas basins of the world.