Evaluating Casing Condition Through Integration of Multi-Finger Calipers and Ultrasonic Imaging with Casing Wear Analysis - A Hybrid Approach

2021 ◽  
Author(s):  
Hassaan Ahmed ◽  
Mohammad Rasheed Khan ◽  
Kamran Rashid ◽  
Abdul Bari ◽  
Syed Dost Ali ◽  
...  
Keyword(s):  
Ultrasonic Imaging ◽  
Hybrid Approach ◽  
Drill String ◽  
Metal Loss ◽  
Coverage Area ◽  
Well Integrity ◽  
Well Trajectory ◽  
Maximum Penetration ◽  
Casing Deformation ◽  
Pulse Echo

Abstract Casing degradation evaluation is of prime importance to ensure well integrity system reliability and sustainability. Multi-finger calipers have been around for more than 50 years and are used to assess internal casing damage. In addition, high resolution ultrasonic imaging, introduced relatively recently, determines casing thickness by transmitting pulse-echo waveforms to initiate thickness-mode of the casing through induction of mechanical resonance. A high-profile exploratory gas well was at stake of being compromised due to fishing and cable sticking incidents in the 7-inch section. In this work, a novel combination of multi-finger caliper and ultrasonic imaging is investigated to accurately determine metal loss with assistance of hybrid threedimensional casing morphological visualizations which is then utilized to validate casing derating models and ensure well integrity. In order to evaluate the casing condition, it was decided to run a 24-finger caliper tool and to make up for loss of coverage area, ultrasonic imaging was employed. In order to process caliper data from various fingers, a three-tier process was applied which includes finger calibration, caliper correction due to eccentricity, finger sticking, finger offset, and lastly statistical analysis was conducted to generate corrosion summary report for metal penetration computations. Next, characteristic of the casing resonance was processed to measure thickness and compared with the nominal thickness to determine metal loss percentage. Furthermore, arithmetical analysis of internal casing radius measurements from both the tools was done to ensure data reliability. Ultimately, combining the measurements, 3D descriptions were generated in order to better characterize localized damage. A multi-physics approach led to a comprehensive characterization of in-situ casing condition. Consistency between internal radius measured by the calipers and deduced by pulse- echo arrivals was observed, improving confidence on the end-product. In the 7-inch casing section, a 40-meters interval was identified to have medium intensity grooves where the maximum penetration was computed to be in excess of 20% of the nominal pipe thickness This groove can be associated with tripping in / out operations of drill string or BHA. Also, the log results agree with the relatively higher side forces across this interval due to increased dog-leg-severity. In addition, cyclic response in radius measurements identified another zone where potential casing deformation (ovalization) near the surface was observed. Results of torque and drag simulations and well trajectory parameters were integrated with casing degradation analysis from the logs which assisted in qualifying well barrier status for the casing.

Analysis Behind Casing to Assess Zonal Isolation and Casing Deterioration in a High Pressure Exploratory Well - ABC to Z of Well Integrity Barrier Evaluation

2021 ◽  
Author(s):  
Hassaan Ahmed ◽  
Mohammad Rasheed Khan ◽  
Abdul Bari ◽  
Kamran Rashid ◽  
Syed Dost Ali ◽  
...  
Keyword(s):  
Flexural Wave ◽  
Metal Loss ◽  
Case Scenario ◽  
Worst Case ◽  
Flexural Mode ◽  
Well Integrity ◽  
Casing Wear ◽  
Drag Analysis ◽  
Pulse Echo

Abstract The UHP exploratory well subject of this study faced with myriad challenges, including fishing, side-tracking, and other undesirable incidents with consequences to the 9-7/8" production casing. Torque and drag analysis, preliminary casing wear simulations, and actual drilling parameters pointed towards multiple uncertainties concerning barrier integrity. Consequently, a multi-physics evaluation was conducted including well-integrity logs in a combination of thickness-mode with flexural-mode of the casing. Signals from these independent measurements are then processed to provide robust interpretation of solid-liquid-gas behind casing using acquired flexural attenuation and acoustic impedance data. In addition, casing wear is quantified by thickness changes measured through the resonance frequency of the waveform and represented in the form of a joint-by-joint corrosion summary, reporting the average metal loss. Furthermore, propagation of flexural wave-fronts as it leaks to the third interface is tracked to produce a unique image of the annulus geometry in terms of casing eccentricity and acoustic velocity of the medium. Subsequently, the former, provides a quantifiable, unique in-situ casing standoff measurement to be used for centralization evaluation. Application of the developed data-integrated workflow allowed for comprehensively analyzing well integrity barrier condition. Cement barriers were assessed with confidence by flexural imaging, which were difficult to determine solely with pulse-echo. Additionally, annulus imaging using third interface-echo (TIE) helped in characterizing the potential causes of casing wear and quality of cement behind casing by providing actual in-situ casing standoff. It was observed that casing wear was at the low side of the wellbore where the casing had the least standoff as shown by flexural waveform TIE arrivals. Moreover, high percentage of metal loss was correlated to regions with centralization lower than 40-50%. Integration of these results with casing side forces and remaining casing strength (under worst case scenario) was performed to evaluate casing endurance for future drilling, production, and injection operations.

Application of LWD Multipole Sonic for Quantitative Cement Evaluation – Well Integrity in the Norwegian Continental Shelf

2021 ◽  
Author(s):  
Subhadeep Sarkar ◽  
Mathias Horstmann ◽  
Tore Oian ◽  
Piotr Byrski ◽  
George Lawrence ◽  
...  
Keyword(s):  
Continental Shelf ◽  
Time Window ◽  
Full Range ◽  
Hybrid Approach ◽  
Bond Quality ◽  
Bond Index ◽  
Early Evaluation ◽  
Well Integrity ◽  
Wide Range ◽  
Norwegian Continental Shelf

Abstract One of the crucial components of well integrity evaluation in offshore drilling is to determine the cement bond quality assuring proper hydraulic sealing. On the Norwegian Continental Shelf (NCS) an industry standard as informative reference imposes verification of cement length and potential barriers using bonding logs. Traditionally, for the last 50 years, wireline (WL) sonic tools have been extensively used for this purpose. However, the applicability of logging-while-drilling (LWD) sonic tools for quantitative cement evaluation was explored in the recent development drilling campaign on the Dvalin Field in the Norwegian Sea, owing to significant advantages on operational efficiency and tool conveyance in any well trajectory. Cement bond evaluation from conventional peak-to-peak amplitude method has shown robust results up to bond indexes of 0.6 for LWD sonic tools. Above this limit, the casing signal is smaller than the collar signal and the amplitude method loses sensitivity to bonding. This practical challenge in the LWD realm was overcome through the inclusion of attenuation rate measurements, which responds accordingly in higher bonding environments. The two methods are used in a hybrid approach providing a full range quantitative bond index (QBI) introduced by Izuhara et al. (2017). In order to conform with local requirements related to well integrity and to ascertain the QBI potential from LWD monopole sonic, a wireline cement bond log (CBL) was acquired in the first well of the campaign for comparison. This enabled the strategic deployment of LWD QBI service in subsequent wells. LWD sonic monopole data was acquired at a controlled speed of 900ft/h. The high-fidelity waveforms were analyzed in a suitable time window and both amplitude- and attenuation-based bond indexes were derived. The combined hybrid bond index showed an excellent match with the wireline reference CBL, both in zones of high as well as lower cement bonding. The presence of formation arrivals was also in good correlation with zones of proper bonding distinguishable on the QBI results. This established the robustness of the LWD cement logging and ensured its applicability in the rest of the campaign which was carried out successfully. While the results from LWD cement evaluation service are omnidirectional, it comes with a wide range of benefits related to rig cost or conveyance in tough borehole trajectories. Early evaluation of cement quality by LWD sonic tools helps to provide adequate time for taking remedial actions if necessary. The LWD sonic as part of the drilling BHA enables this acquisition and service in non-dedicated runs, with the possibility of multiple passes for observing time-lapse effects. Also, the large sizes of LWD tools relative to the wellbore ensures a lower signal attenuation in the annulus and more effective stabilization, thereby providing a reliable bond index.

Ultrasonic Imaging Using the Instantaneous Frequency of Pulse-Echo Signals

1985 ◽  
pp. 487-496 ◽  
Author(s):  
D. A. Seggie ◽  
G. M. Doherty ◽  
S. Leeman ◽  
L. A. Ferrari
Keyword(s):  
Instantaneous Frequency ◽  
Ultrasonic Imaging ◽  
Pulse Echo

Drill String Vibrations Due to Intermittent Contact of Bit Teeth

1963 ◽  
Vol 85 (2) ◽  
pp. 187-194 ◽  
Author(s):  
P. R. Paslay ◽  
D. B. Bogy
Keyword(s):  
Experimental Data ◽  
Penetration Rate ◽  
Drill String ◽  
String Vibrations ◽  
Order Of Magnitude ◽  
Intermittent Contact ◽  
Maximum Penetration ◽  
Sufficient Magnitude ◽  
Force Excitation ◽  
Practical Measurement

An analysis of the longitudinal forces and the resulting longitudinal motions of an idealized drill string is presented. The only external force excitation considered occurs at the bit and is due to the intermittent contact of the teeth with the bottom of the hole. Attention has been restricted to the following two salient possibilities: 1 - Excitation at the bit may develop oscillating forces at the bit with amplitudes of the same order of magnitude as those of the bit load. 2 - Appreciable bit load variation may be detected by instruments which measure the motion of the drill string near its top. The first possibility is important if maximum penetration rate is to be achieved, and the second possibility is important in implementing practical measurement of the phenomenon. From the results of the specific example considered in this report, it is concluded that possibilities 1 and 2 may occur in sufficient magnitude to be influential, but experimental data on the actual bit motion and the damping will be required to evaluate the effect. The analysis is presented in such form that the influence of the various parts of the system can easily be evaluated.

Casing Shear Deformation Based on Micro Seismic Data

2019 ◽  
Vol 944 ◽  
pp. 1011-1019
Author(s):  
Yi Jin Zeng ◽  
Yan Xi ◽  
Shi Dong Ding ◽  
Jun Li ◽  
Xin Yu Hao ◽  
...  
Keyword(s):  
Shear Deformation ◽  
Seismic Data ◽  
Influential Factors ◽  
Natural Fracture ◽  
Well Trajectory ◽  
Cement Sheath ◽  
Dip Angle ◽  
Casing Deformation ◽  
And Control ◽  
Slip Distance

Casing shear deformation, which is caused by fault slipping, is the main morphology of casing deformation occurred during multistage fracturing. In order to determine the relationship between fault slipping and casing shear deformation, the micro seismic data collected from engineering field which can reflect the reality of the formations was analyzed. A new numerical model was developed, and the influential factors on casing shear deformation were studied, including the fault slip distance of lower and upper interface, fault dip angle, the thickness of cement sheath and casing. The results of research shows that: (1) Fault is easily activated by fracturing, which was the main reason of casing shear deformation; (2) The greater the fault dip angel, the slip distance, the greater the casing shear deformation; (3) Increasing the wall thickness of casing or cement sheath is beneficial to decrease the degree of the shear deformation; (4) Two ways can be used to avoid and control the casing shear deformation, one is keeping the designed horizontal segment of well trajectory keep away from fracture-developed area, or be parallel to natural fracture, the other is using stage cementing technology. Research results can provide important reference for design and control of casing integrity during multistage fracturing in shale gas wells.

scholarly journals Medical ultrasound: imaging of soft tissue strain and elasticity

2011 ◽  
Vol 8 (64) ◽  
pp. 1521-1549 ◽  
Author(s):  
Peter N. T. Wells ◽  
Hai-Dong Liang
Keyword(s):  
Soft Tissue ◽  
Soft Tissues ◽  
Ultrasonic Imaging ◽  
Low Frequency ◽  
Radiation Force ◽  
Breast Disease ◽  
Published Data ◽  
Tissue Strain ◽  
Low Frequency Vibration ◽  
Pulse Echo

After X-radiography, ultrasound is now the most common of all the medical imaging technologies. For millennia, manual palpation has been used to assist in diagnosis, but it is subjective and restricted to larger and more superficial structures. Following an introduction to the subject of elasticity, the elasticity of biological soft tissues is discussed and published data are presented. The basic physical principles of pulse-echo and Doppler ultrasonic techniques are explained. The history of ultrasonic imaging of soft tissue strain and elasticity is summarized, together with a brief critique of previously published reviews. The relevant techniques—low-frequency vibration, step, freehand and physiological displacement, and radiation force (displacement, impulse, shear wave and acoustic emission)—are described. Tissue-mimicking materials are indispensible for the assessment of these techniques and their characteristics are reported. Emerging clinical applications in breast disease, cardiology, dermatology, gastroenterology, gynaecology, minimally invasive surgery, musculoskeletal studies, radiotherapy, tissue engineering, urology and vascular disease are critically discussed. It is concluded that ultrasonic imaging of soft tissue strain and elasticity is now sufficiently well developed to have clinical utility. The potential for further research is examined and it is anticipated that the technology will become a powerful mainstream investigative tool.

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