Schlumberger

High Pressure, High Temperature (HPHT)

We develop lifecycle profiles that begin with customer collaboration so that we are able to better understand all aspects of the task at hand. Operational profiles are critical in achieving high reliability, and in these we describe in detail the operating envelope, expected quality of the results, and duration of the job.

Duration of exposure, a critical HPHT parameter

The length of time that a product must withstand the hostile environment is a crucial factor. For example, logging and testing tools and drilling muds are exposed for a limited time but cement and completions products must survive for many years. It is also essential to repeatedly cycle the product through its full range of temperature and pressure to ensure consistent performance over its operating life.

Mission-specific HPHT tests

Laboratory evaluations fall into three principal categories:

  • Fluids: Testing under simulated downhole conditions must determine if the fluid can be prepared and properly placed in the well and whether it will be sufficiently stable to perform its intended functions. The testing protocol is often complex, involving rheology, filtration, corrosion, and mechanical-property evaluations.
  • Mechanical devices: This category includes seals, screens, and packers, along with rotating and reciprocating parts such as shafts, pistons, valves, and pumps. In addition to HPHT exposure, qualification testing includes mechanical shocks and contact with hazards such as hydrogen sulfide (H2S); carbon dioxide (CO2); and erosive, particle-laden fluids. Seals that can survive up to 260 degC [500 degF] under static conditions are only rated to 150 degC [300 degF] for dynamic applications in a mud environment with some sand inclusions.
  • Electronic components and sensors: Engineers must determine the operational time limit under simulated downhole conditions. The key challenge involves the stability of plastic or composite materials that provide modern electronics with structural integrity and insulation.

Extreme qualification process for maximum reliability

The qualification process must simulate the harshest conditions that may be encountered and is customized for the product. Numerous tests are conducted at a system level, as well as for individual components, electronics boards, and subassemblies, often extending over several weeks or months. They can include

  • thermal aging
  • thermal cycling
  • pressure cycling
  • thousands of shocks along each axis at normal and elevated temperatures
  • vibration at multiple frequencies and temperatures
  • cold storage
  • low- and high-temperature operations.

The process concludes with extended reliability testing, during which the equipment is subjected to a lengthy operational test under cycles of temperature, power, functional load, and shock. An extensive database compiled from these tests is used to define preventative maintenance procedures, maximizing reliability at each deployment.

Increased Production 500% in HPHT Well

ThermaFRAC shear-tolerant fracturing fluid improves proppant transport, resulting in 500% production increase for Pakistan operator. Read case study

HPHT- Science of Extremes

HPHT Chart
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