Impact of Casing Pressure Test After Waiting on Cement on Cement Bond Quality

2020 ◽  
Author(s):  
Mikhail Borisovich Vavilov ◽  
Yulia Viktorovna Sekacheva ◽  
Vladimir Igorevich Chernov ◽  
Kirill Vladimirovich Lyutikov ◽  
Alexander Sergeyevich Perebatov
Keyword(s):  
Bond Quality ◽  
Pressure Test ◽  
Casing Pressure ◽  
Cement Bond Quality

Impact of Casing Pressure Test After Waiting on Cement on Cement Bond Quality (Russian)

2020 ◽  
Author(s):  
Mikhail Borisovich Vavilov ◽  
Yulia Viktorovna Sekacheva ◽  
Vladimir Igorevich Chernov ◽  
Kirill Vladimirovich Lyutikov ◽  
Alexander Sergeyevich Perebatov
Keyword(s):  
Bond Quality ◽  
Pressure Test ◽  
Casing Pressure ◽  
Cement Bond Quality

Cement Conundrum: Valuable Lessons Learned for Sustaining Production

2021 ◽  
Author(s):  
Siti Najmi Farhan binti Zulkipli
Keyword(s):  
New Technology ◽  
Processing Parameters ◽  
Lessons Learned ◽  
Critical Element ◽  
Well Performance ◽  
Bond Quality ◽  
Quality Issue ◽  
Cement Integrity ◽  
Production Period ◽  
Cement Bond Quality

Abstract Addressing wellbore integrity through cement evaluation has been an evergreen topic which frequently catches major operators by surprise due to premature water or gas breakthrough causing low production attainability from the wells. Managing idle well strings arising from integrity issues is also a challenge throughout the production period. The remedial solutions to these issues do not come conveniently and require high cost during late life well intervention which often erodes the well economic limit. A critical element of wellbore barrier which is cement integrity evaluation is proposed to be uplifted and given a new perspective to define success criteria for producer wells to achieve certain reserves addition and production recovery. This paper will highlight integrated factors affecting cement bond quality, impact to well production, potential remedies for poor cement bond observed leveraging on the enhanced workflow and new technology and way forward to proactively prevent the unwanted circumstances in the first opportunity taken. A set of recommendations and prioritization criteria for future cement improvement will be also highlighted. Several case specific wells logged with variable cement bond evaluation tools are re-assessed and deep-dived to trace the root causes for unsatisfactory cement bond quality observed which include reservoir characteristics, understanding anomalies during drilling and cementing operation, identifying cement recipe used, log processing parameters applied and observing best practices during cementing operation to improve the quality. New and emerging cement evaluation technology inclusive of radioactive-based logging to meet specific well objectives will be also briefly discussed in terms of differences and technical deliverables. Looking at each spectrum, results show that there are several interdependent factors contributing to poor cement bond quality observed. Accurate understanding of formation behavior, designing fit-for-purpose cement recipe and adequate planning for cementing operation on well-by-well basis are among the top- notch approaches to be applied for an acceptable cement bond quality and placement. Statistics show that 27% to 64% of production attainability is achieved by wells with good cement quality within the first 3 months of production and this increases to 85% to 98% up until 7 months of production period, while only 12% production attainability achieved for those wells with adverse cement quality issue. In another well, water cut as high as 47% since the first day of production is observed which keeps increasing up to 40% thereafter. In a nutshell, cement evaluation exercise shall not be treated as vacuum, instead it requires an integrated foundation and close collaboration to materialize the desired outcomes. Arresting the issue with the right approach in the first place will be the enabler for optimum well performance and productivity to exceed the recovery target.

How to Evaluate the Effect of Mud Cake on Cement Bond Quality of Second Interface?

2007 ◽  
Author(s):  
Ma Yong ◽  
Cui Mao Rong ◽  
Guo Yang ◽  
Shi Qing ◽  
Li Li
Keyword(s):  
Bond Quality ◽  
Mud Cake ◽  
Cement Bond Quality

scholarly journals Analytical and Experimental Investigation of the Critical Length in Casing–Liner Overlap

2019 ◽  
Vol 11 (23) ◽  
pp. 6861 ◽  
Author(s):  
Mustafa Al Ramadan ◽  
Saeed Salehi ◽  
Chinedum Ezeakacha ◽  
Catalin Teodoriu
Keyword(s):  
Critical Length ◽  
Fluid Migration ◽  
Test Duration ◽  
Gas Migration ◽  
Gas Leakage ◽  
Pressure Test ◽  
Seal Assembly ◽  
Casing Pressure ◽  
The Cost ◽  
Selection Of

Offshore drilling operations exhibit various difficulties attributed to shallow flows worldwide. One of the most common practices for drilling offshore wells is to use liners and liner hangers rather than using full casing strings. This reduces the cost of drilling operation. Liners and liner hangers are required to pass certain standards prior to their deployment in the field. This ensures their ability to withstand harsh downhole conditions and maintain the integrity of the well. A liner hanger contains an integrated seal assembly that acts as a barrier to prevent fluid migration. The cement that is placed within the casing–liner overlap is also considered a barrier, and it is critical that it maintains the integrity of the well by mitigating fluid migration to other formations and to the surface. The failure of this dual barrier (cement and seal assembly) system to seal the annular space can result in serious problems that might jeopardize a well’s integrity. Typically, in field applications, the length of a casing–liner overlap is chosen arbitrarily. In some cases, shorter overlaps (50 to 200 ft) are chosen because of the lower cost and easy identification of leaks during pressure tests. However, some loss of well control incidents (particularly the incident that motivated this study) have been linked to fluid leakages along the casing–liner overlap. This paper investigates the critical length of the casing–liner overlap by modeling gas leakage through the cement placed within the overlap using analytical and experimental approaches. Leakage scenarios were developed to mimic gas migration within the cement in the casing–liner overlap. The results showed that the longer the casing–liner overlap, the higher the leakage time. The results also showed that the current casing pressure test duration of 30 min may not be adequate to verify the integrity of the cement within the overlap. Based on the results and analyses, it is recommended to increase the pressure test duration to 90 min. In addition, the results suggest that the length of the casing–liner overlap should not be less than 300 ft to maintain the integrity of the well in the case of gas influx. Further details are highlighted in the results section. In practice, the current rationale behind the selection of a casing–liner overlap length is not sustainable. Thus, the major advantage of this study is that with field data, it provides both scientific and research-based evidence that can be used to inform the decision behind the selection of the casing–liner overlap length, especially in gas migration-prone zones.

Improvement and application of ultrasonic cement bond quality evaluation method

2016 ◽  
Author(s):  
Hou Zhenyong* ◽  
Hao Xiaoliang* ◽  
Ma Huanying* ◽  
Li Jiling* ◽  
Niu Peng* ◽  
...  
Keyword(s):  
Quality Evaluation ◽  
Evaluation Method ◽  
Bond Quality ◽  
Cement Bond Quality

New Toe Sleeve Enables True Casing-Pressure Test in an Eagle Ford Shale Well: A Case Study

2015 ◽  
Author(s):  
Ben Wellhoefer ◽  
Sean Canning ◽  
Travis Alkek ◽  
Garner Haydell ◽  
Molly Wharton Smith
Keyword(s):  
Eagle Ford Shale ◽  
Eagle Ford ◽  
Pressure Test ◽  
Casing Pressure

Well integrity and the correlation between borehole breakouts, drilling-induced tensile fractures and cement-bond log response

2012 ◽  
Vol 52 (2) ◽  
pp. 696
Author(s):  
Roger Marsh ◽  
Abbas Khaksar ◽  
Oliver Gaede ◽  
Adrian White ◽  
Chris Wilson ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Mechanical Analysis ◽  
Bond Quality ◽  
Well Integrity ◽  
Borehole Breakouts ◽  
Tensile Fractures ◽  
Cement Bond Quality

Traditionally, image logs are acquired for sedimentary and structural analysis and more recently geo-mechanical analysis. Caliper logs are usually acquired for cement volume information and borehole condition information with pad tools. In general, cement bond logs have been the only logs used for the assessment of cement bond quality and thereby well integrity at the end of the well construction phase. Cement bond logs occasionally produce puzzling results—the cement job parameters indicate a successful cement job, yet the cement bond log indicates otherwise. In some circumstances, the presence of a micro-annulus can cause the appearance of a bad bond. In others, the causes of such cement bond log responses are less obvious. Wellbore breakouts and drilling induced tensile fractures can cause drilling problems such as increased losses, washouts and cave-ins; however, their association with cement bond quality is not always appreciated. This dataset consists of LWD StarTrak and Lithotrak caliper data and EWL Wellbore Geometry Instrument (WGI) data and Segmented Bond Tool (SBT) data The data shows extensive zones of borehole breakouts as well as tensile fractures, some of which exist in areas without breakouts. The SBT pad data shows large areas of poor bond between relatively thin-cemented sections. The VDL data shows formation arrivals that became more pronounced with depth. When the data are compared, the zones that showed tensile fractures coincided with zones showing poor bond. The zones showing no tensile fractures or breakouts were also the zones showing good cement bond.

Advances in Cased Hole Acoustic Slowness Measurements and Its Application in a Depleted Reservoir Drilled with Highly Inclined Well: A Case Study from Offshore Malaysia

2021 ◽  
Author(s):  
M. Amin C. A. Razak ◽  
Ayham Ashqar ◽  
Saikat Das ◽  
Ahmad Izzuddin B. Yusof ◽  
Arie Purba Tata ◽  
...  
Keyword(s):  
Data Quality ◽  
Data Acquisition ◽  
Low Frequency ◽  
Flexural Wave ◽  
Bond Quality ◽  
Acoustic Data ◽  
Challenging Environment ◽  
Open Hole ◽  
Well Data ◽  
Cement Bond Quality

Abstract Acquiring acoustic slowness data in open & cased hole and a reliable cement bond log in one run without jeopardising data quality or increasing rig time is desired for fast and optimize data acquisition. This paper reviews the steps taken to ensure acoustic slowness and cement bond data acquisition fulfils the objective, while minimising the cost in an offshore challenging environment for formations with variable acoustic velocities that could be masked by strong casing arrivals. Crossed dipole acoustic logging is typically preferred to acquire within open hole environment for best quality signal. However, due to drilling challenges this could not be done in the subject well. Data was acquired in 6in open hole and 7" liner (8.5 in Open hole behind) cased hole section together in one run. Shear slowness in slow formation requires propagation of the low frequency dipole flexural wave whereas compressional slowness acquisition and cement bond evaluation requires high frequency monopole data. An improved understanding of cased-hole acoustic modes allowed developing the ability to transmit acoustic energies at optimal frequencies in order to acquire formation slowness concurrently with cement bond. Acoustic data quality in cased hole is dependent on cement bond quality. Poor bonding or presence of fluid between casing and the formation inserts noise in the data by damping the acoustic signal. Hence, understanding of the cement bond quality is critical in interpreting the cased hole acoustic data. The low amplitude of the compressional first arrival indicated the presence of cement bonded with the casing. Absence of casing ringing signal at the beginning and presence of strong formation signal in the VDL indicated good bonding of cement with formation. Filtration of the cased hole acquired semblances were necessary to remove the casing and fluids noises. Acquired data shows good coherency and continuous compressional and shear slowness's were extracted from the good quality semblances. This integrated strategy to acquire the formation slowness and to evaluate the cement bond quality and top of cement allowed meeting all objectives with one tool in single run. The risk of casing waves that could have masked the formation slowness signal was mitigated by transmitting acoustic energies at optimal frequencies with wider bandwidth followed by the semblance processing. The effects of borehole ovality, tool centralization, or casing centralization on waveform propagation were studied to supplement the interpretation. The first times strategic logging application in PETRONAS allowed time and cost saving and fulfilled all data acquisition plan. Data quality assurance and decision tree allowed drafting a workflow to assure data quality. This solution showed importance of smart planning to maximise advanced tools capabilities to acquire acoustic slowness data and cement evaluation in single run in offshore challenging environment.

Sign in / Sign up

Export Citation Format

Share Document