A facility that processes hydrocarbons needs an inspection program not only to meet regulatory requirements, but also to protect its bottom line by actively managing risk. While this goal may be a foregone conclusion, its achievement is not. So, what goes into a well-designed inspection program? And what does it produce? How can the most value be derived from inspection dollars?
As a part of their regulatory remit, BSEE is undertaking inspections to ensure the integrity of the structures and processing equipment on the OCS are properly maintained to continue safe operations with no harm to the environment. As a part of this undertaking both scheduled annual inspections, and periodic and unannounced inspections are performed.
There are many production reservoirs that produce high levels of hydrogen sulfide (H2S). Some of these fields know before initial production that there will be high levels of H2S and thus are able to design and manage accordingly; however, some fields will begin producing an increasing amount of H2S following water injection. These fields are more difficult to manage and require a means of prediction to help make cost-effective project decisions. At GATE Energy, we have the technical knowledge and experience to apply our own approach to souring prediction which can enable design and operational decisions to be made to mitigate the risks associated with such H2S production.
There are many projects that leverage water injection or waterflood (WF) as a secondary recovery tool to increase oil production returns. Many of these projects’ economic viability is intrinsically linked to the ability to inject large volumes of water into the reservoir as a means of oil drive and pressure maintenance. For these fields, it is vital that the integrity of the water injection system is maintained through fit-for-purpose material selection and asset integrity management processes.
Development of an integrity management program is initiated during design phase, which includes selecting the appropriate materials, establishing requirements for corrosion, erosion, flow assurance and process along with associated maintenance, monitoring and surveillance requirements. In this GATEKEEPER, the philosophy around the materials selection and corrosion monitoring is discussed as the primary design barrier to corrosion and cracking in critical parts of a subsea system.
American Petroleum Institute (API) 5CT high strength steels are extensively used for casing strings in wells subjected to high cyclic hydraulic fracturing loads. While non-sour grades of API steel such as P110 casing strings have been used satisfactorily for well construction, standard API P110 connections have seen higher rates of failures than pipe body failures in shale wells that require hydraulic fracturing. P110 pipe body and connection failures have also been experienced in cases where poor manufacturing practices have been employed to produce P110 steel casings and connections used in wells subjected to these high hydraulic fracturing loads.
Martensitic stainless steels continue to be one of the most widely used corrosion resistant alloys in oil and gas developments. Determining if a martensitic stainless steel is acceptable in an unproven environment requires testing to confirm, but predicting the outcome of a given test environment is often initially based on personal experience rather than a qualitative and quantitative assessment.
Triaxial evaluation of wellbore loads is used extensively for casing and tubing string design and analysis. A triaxial based collapse strength method was recently adopted by the American Petroleum Institute (API), and an addendum issued to API Technical Report 5C3 (TR 5C3). The triaxial based collapse formula incorporates internal pressure and axial load into the calculation of casing and tubing collapse strengths. Casing and tubing that are subjected to combined loads have higher collapse strength than previous formulas would predict, permitting the use of thinner walled, or lower strength, pipe than formerly required.