With the emergence of high resolution magnetic pigs with sensors on the basis of Hall transducers, it is now possible to solve a set of tasks on the identification of defects of different types for one run of a smart pig. The defects are as follows:
All the above-mentioned advantages coupled with the use of the state-of-the-art achievements in sensor technology and microprocessor technology, achievements in the field of miniaturization, use of high-tensile and wear-proof materials, allowed developing a new generation of magnetic inspection pigs that have high technical characteristics and can register and measure geometrical parameters of all types of defects with a high degree of certainty. The practical use of such pigs resulted in a situation when pipeline operators (such as BP, SHELL, PHILIPS, etc.) stopped using ultrasound technologies. Needless to say that gas pipeline operators did stop using them as well since the use of ultrasound technologies requires expensive “batching” (liquid plug creation) procedures to be performed, which also leads to economic losses related to the violation of transported product pumping-over operation schedules
The refusal to use ultrasound technologies is mainly due to a significant economic benefit – a single pig run is always less expensive than two pig runs because (amongst other things) it allows reducing Customer’s indirect expenses on the organization of an additional run and follow up of an inspection pig. In such a case the Customer does not lose any information and if it uses technical innovations it even receives information of higher quality.
The implementation of technical innovations in inspection MFL pigs resulted in new achievements:
А) The resolution capacity of magnetic MFL inspection scrapers:
Many pigs in the diagnostics market (including ultrasound ones) have a standard resolution of 3.3х8.0 accordingly or even worse. When this equipment is used for measuring parameters of a defect that has geometrical dimensions of 60х60mm, 18 measurements in the longitudinal direction will be made, at the same time 7 sensors will be in the defect’s area in the traversal direction.
So we will receive 24 measurements with the use of 10 sensors for a magnetic MFL pig.
An important benefit of this high resolution of MFL pigs is a capacity to register informatio with a high degree of certainty deep pittings (“puncture”, weld hole) that lead to pipeline leakage and are the most often reason for accidents at field pipelines (A report of D.Eng.Sc., Professor V.N. Antipyev, Director of the Expert Organization “Energy-2” at the seminar “New Technologies and Materials for the Construction and Repair of Pipelines” according to the 5FP program of the European Commission, Tyumen, November 2003).
In this regard, the use of magnetic NDT with a high resolution for inspecting field pipelines is considered to be the best choice.
B) Transducer scanning (sampling) frequency – 2,000 Hz.
The use of transducer scanning at a high frequency coupled with the use of the dynamic scanning system (the frequency is directly proportional to the flaw detector’s velocity) guarantees a stable resolution for MFL pigs at 2.5mm in the longitudinal direction covering the whole range of velocities of up to 5 m/s.
Important remark: Declaring a resolution to be at 3.3 mm for the majority of diagnostics companies at a transducer scanning frequency of 300 Hz means that the declared resolution is ensured only at velocities of up to 1 m/s. The resolution becomes worse at higher velocities and defect identification and measurement specifications are not complied with!
Example: Equipment with outdated electronics used by the majority of diagnostics companies has a resolution capacity in the longitudinal direction that decreases at a velocity of 2 m/s and a scanning frequency of 300 Hz to 6.6 mm and at a velocity of 4 m/s – to 13.3mm! (Defects larger than 10mm are not identified at all). Inspection MFL equipment has a stable resolution of 2.5 mm at a velocity of up to 5 m/s.
Demand explanations as to compliance with specifications for diagnostics pigs at a velocity of more than 1 m/s
C) Nowadays only when you use MFL pigs you meet the requirement of the Pipeline Operator Forum to specifications of smart inline pigs and to the performance of works in general (Version 2.1 as of November 6, 1998 is attached), as well as the obligatory requirement to control a pipeline wall’s magnetization level directly in the course of diagnostics. Moreover, the said requirement regulates a required pipeline wall’s magnetization range which provides for the registration of defects with a precision of 0.95 and it is possible to perform a linear calibration of such measurements. This range is from 10 to 30 kA/m.
When a magnetization level is lower, information cannot be accurately calibrated with the required precision. This means that some defects, which will be identified, will be measured with a precision not in accordance with the declared specifications. Some defects in the form of deep “needle-like” pitting can be missed at all. Experts of leading pipelines operators do know about it.
Many diagnostics companies just do not specify magnetization parameters in characteristics of their diagnostics equipment.
“NTC ”Neftegazdiagnostika”, LLC, proposes to run diagnostics of pipelines with specific wall thickness parameters that ensures a magnetization range to be from 10 kA/m for the maximum wall thickness to 30 kA/m for the minimum wall thickness and to provide a true magnetization schedule along the route right after the run.
D) “NTC ”Neftegazdiagnostika”, LLC, offers its services on pipelines mapping with a high precision. As a result the Customer receives true profiles of pipelines beddings (vertical and horizontal), correlation of all registered peculiarities of a pipelines, including defects, in relative and world geographic coordinates, identification of such reference points as roads, water obstacles, communications, etc.
By using mapping information you significantly reduce the time required to find a defect (the search is carried out according to the coordinates with the use of GPS equipment) and cut excavation expenses. A pipeline can be correlated to the world geographic map (visualization). When conducting reinspections, it is possible to identify sections with pipelines shearing caused by external effects (landslides, underwater line sections, pump outs in frozen soil and swamplands), which are characterized by a pipeline material being in a stress condition.
E) All modern magnetic inspection MFL pigs, starting from the diameter of 16" and more, have a single-section design and independent pig launcher kicking means. All MFL pigs, regardless of their intended use, are capable of passing turns (bends) at a 90° angle and 1.5D radius, as well as segmented bends with an angle of up to 30°. They are distinguished by an increased mechanical stability of their structural components that reduces the risk of equipment getting stuck in a pipeline or of receiving low-quality or incomplete information due to damaged sensors or cable connections, to a minimum, which also reduces the likelihood that reruns will be necessary.
AFD inspection scrapers for traversal magnetization with a unique longitudinal and traversal resolution and absence of any spaces between main sensors. It is achieved because sensors are placed in a circle in two lines between the magnets, it provides a 100% guarantee that the full surface of a pipe wall will be covered.
A) The resolution capacity of AFD inspection scrapers for traversal magnetization:
B) Transducer scanning (sampling) frequency: — 2,000 Hz.
These are the first scrapers in the market that can truly identify stress corrosion and to show with a high degree of probability very thin longitudinal cracks that often lead to pipeline breaks. It is no secret that scrapers of the first generation do not possess the sensitivity that is necessary to identify narrow longitudinal-oriented defects and stress corrosion.
27.03.2016 - 05.04.2016 Viktor Leshchenko, Director General “NTC “Neftegazdiagnostika” LLC, visited Calcutta (India) to participate ...
A sole agency agreement was signed between NTC NEFTEGAZDIAGNOSTIKA LLC and Abdel Hadi Abdullah Al-Qahtani & Sons Company
On September 12, the laboratory VNIPI "VZRYVGEOFIZIKA" conducted New website launched! Inline inspection of main gas line Nord Stream pipeline 1-East, Dn 1220×34.6/41 mm, 1224.4 km long Inline inspection of main gas line Nord Stream pipeline 2-East, Dn 1220х34.6/41 mm, 1224.4 km long Segment 1, gas pipeline Ø 1220 mm. OPF – BS-2, 295 km long. Segment 2, gas pipeline Ø 1220 mm. BS-2 – OET, 328 km long. Inline inspection of the offshore oil pipeline "OIFP D-6 – oil gathering facility "Romanovo", Dn 273x18, 51.812 km long. Integrated diagnostics of sub-sea oil pipeline "OIFP – SPM, oil field n.a. Yu. Korchagin" started. Installation and dismantling of temporary pig launchers/receivers Pipeline cleaning, gauging, geometry inspection, magnetic pig inspection Subsea external inspection using ROVs Cleaning of the offshore oil pipeline "OIFP – SPM, oil field n.a. Yu. Korchagin", Dn 325×16.
New website launched!
Inline inspection of main gas line Nord Stream pipeline 1-East, Dn 1220×34.6/41 mm, 1224.4 km long
Inline inspection of main gas line Nord Stream pipeline 2-East, Dn 1220х34.6/41 mm, 1224.4 km long
Segment 1, gas pipeline Ø 1220 mm. OPF – BS-2, 295 km long.
Segment 2, gas pipeline Ø 1220 mm. BS-2 – OET, 328 km long.
Inline inspection of the offshore oil pipeline "OIFP D-6 – oil gathering facility "Romanovo", Dn 273x18, 51.812 km long.
Integrated diagnostics of sub-sea oil pipeline "OIFP – SPM, oil field n.a. Yu. Korchagin" started.
Installation and dismantling of temporary pig launchers/receivers
Pipeline cleaning, gauging, geometry inspection, magnetic pig inspection
Subsea external inspection using ROVs
Cleaning of the offshore oil pipeline "OIFP – SPM, oil field n.a. Yu. Korchagin", Dn 325×16.