A Curious Case of Addressing Well Integrity Issue with Production Logging

2021 ◽  
Author(s):  
Gaurav Agrawal ◽  
Ajit Kumar ◽  
Vibhor Verma ◽  
Alok Mishra ◽  
Vikram Gualti ◽  
...  
Keyword(s):  
Water Entry ◽  
Entry Point ◽  
Diagnostic Tools ◽  
Complex Environments ◽  
Well Integrity ◽  
Cement Integrity ◽  
Water Cut ◽  
Challenging Situation ◽  
Complex Scenario ◽  
Integrity Issue

Abstract The productive life of a well can be affected by deterioration of the well integrity which can be due to casing/tubing corrosion, casing damage during drilling/ work over, packer failure, plug failures, cement integrity issues etc. Remedial measures can be executed if the nature of problem is diagnosed. One can receive early warning of a potential problem and obtain data for determining a specific restoration program by running well integrity diagnostic tools. There are various well integrity tools available to cater evaluation needs at present times with different working principles and targeting different well integrity problems such as casing/tubing and cement integrity. However, in challenging situation and complex environments, the tools may not provide complete diagnostics. Production logging can be an effective tool in such scenarios by mapping the flow behaviour in the wellbore and can provide a better idea of the wellbore problems. The well "A" is a development well which was drilled (max angle~ 27º) and completed in the interval X345-X349m and X362-X368m to exploit gas from the reservoir ABC. During initial testing it produced @ 1, 67,000 m3/d with FTHP of 2348psi. Later after acid job rate increased to 2,20,000 m3/d but later well had frequent water loading problem and required frequent activation / stimulation. The well has good reservoir zones as identified on the OH logs, hence, to diagnose the reason for water production, PLT was planned in the well in 2015. The well was producing 1,00,000 m3/d of gas at an FTHP of 1181psi during that time. Annulus pressure build-up was also observed in the well suggesting integrity issue with packer/tubing. During the PL run, it was observed that the packer has fallen and settled across one the perforation and the flow was observed to be ongoing from inside as well as outside the packer element making the flow interpretation tricky. A proper interpretation was carried out taking into consideration all available data and water entry point was confirmed. Based on the results, a well intervention was carried out and after the job, well started producing 1,50,000 m3/d of gas with 0% water cut whereas before it was producing 1,00,000 m3/d of gas with 1900 BPD of water. Thus, the intervention resulted in production enhancement by 50% and reduction in water cut by 100%. This paper highlights the proper analysis of the recorded data for diagnosis of the flow condition in an adverse and complex scenario and finding out the water entry point for a proper remediation of the well integrity and production issue.

scholarly journals Securing Annulus Abnormal Pressure Build-up (APB) with Polymer Plug; a Case Study

2020 ◽  
Vol 1 (2) ◽  
pp. 62
Author(s):  
Ganesha R Darmawan
Keyword(s):  
Operating Pressure ◽  
Gas Migration ◽  
Well Control ◽  
Well Integrity ◽  
Abnormal Pressure ◽  
Additional Challenge ◽  
Cement Plug ◽  
Planning And Operation ◽  
Integrity Issue

The life cycle of a production well was facing challenges related to well integrity issue where A-Annulus pressure tracking the tubing pressure and increased repeatedly above the Maximum Allowable Wellhead Operating Pressure (MAWOP). Several well control operations were executed to reduce A-Annulus abnormal pressure build-up (APB) with no success.Literature and well historical studies were performed in order to secure this well, normal bleed and lube was ruled out owing to several attempts already performed for more than a year, but the APB keep on appearing after 2-4 months. Bullheading is not a viable option to kill the well. Well securing planned and prepared with some options such as, mechanical barriers/plugs, cement plug or polymer plugs as temporary plug to avoid APB re-occurrence. There were some constrains in operation planning that need to be addressed carefully, with additional challenge of tight injectivity as if it was a closed system.The polymer plug successfully stops the gas migration to surface, and secured the well from any reoccurrences of APB. The details of well control histories, operation design and planning and operation execution with the complete results and evaluation will be presented in this paper.

Cement Evaluation in Highly Laminated and Multi-Stacked Sandstone Reservoirs: The World First Novel Approach Using Dual-Physics Cement Bond Assessment

2021 ◽  
Author(s):  
Siti Najmi Farhan binti Zulkipli ◽  
Saikat Das ◽  
Emma Smith
Keyword(s):  
Acoustic Wave ◽  
Cross Flow ◽  
Integrated Approach ◽  
Fluid Loss ◽  
Comprehensive Overview ◽  
Novel Approach ◽  
Average Shear ◽  
Zonal Isolation ◽  
Cement Integrity ◽  
Water Cut

Abstract Advances in cement recipe, additives and cementing technology including light weight cement, ultra-low fluid loss cement blend and improved cement to mud rheology mixing to seal the continuous liquid channels have prompted the industry to find an innovative way to evaluate the cement bond and integrity with a more robust and integrated approach. Evaluating cement bond behind casing based on single tool platform had shown some inherent uncertainties mainly due to borehole effects, tool eccentralization and processing variation. This paper will highlight few case studies on the application of both electromagnetic acoustic wave (EMAT) and ultrasonic cement evaluation logs including the world's first tool combination in single run to enhance understanding on cement integrity and optimize the perforation interval for production. Channeling and microannulus occurrences whether dry or wet are the most common features in cement integrity evaluation and yet poorly characterized to prevent any unwanted cross-flow or adverse impact to production. Electromagnetic acoustic wave cement evaluation in combination with an ultrasonic tool allow direct quantification of compressional, shear and flexural attenuation properties of cement downhole as well as acoustic impedance and microdebonding feature of the cement. Separation between average shear and flexural attenuation curves may indicate presence of microannulus depending on the extent of the separation without any requirement of additional pressurized logging pass. Parameter threshold determination based on shear and flexural attenuation cross-plot also indicates severity of cement microdebonding. Results showed that good production rate with lower water cut and low GOR reading had been achieved from specific perforated zones in the well. Electromagnetic acoustic wave and ultrasonic cement evaluation tools had successfully defined the zonal isolation layers as thin as 2 to 3 meters along the wellbore and optimized the perforated zones to avoid any liquid channeling or premature water and gas breakthrough into the wells, which can affect the production attainability and drainage efficiency from particular reservoirs. In a nutshell, combination of EMAT acoustic wave and ultrasonic cement evaluation principles prove to provide a more comprehensive overview on the cement bond integrity behind the casing. Having two independent downhole measurement which complement each other will reinvent the effort in cement bond assessment for complex reservoir environment which is susceptible to interpretation ambiguity.

scholarly journals Real-Time Well-Integrity Monitoring Using Fiber-Optic Distributed Acoustic Sensing

SPE Journal ◽  
2019 ◽  
Vol 24 (05) ◽  
pp. 1997-2009 ◽  
Author(s):  
T.. Raab ◽  
T.. Reinsch ◽  
S. R. Aldaz Cifuentes ◽  
J.. Henninges
Keyword(s):  
Life Cycle ◽  
Strain Rate ◽  
Real Time ◽  
Fiber Optic ◽  
Axial Strain ◽  
Fiber Optic Cable ◽  
Integrity Monitoring ◽  
Well Integrity ◽  
Distributed Acoustic Sensing ◽  
Cement Integrity

Summary Proper cemented casing strings are a key requirement for maintaining well integrity, guaranteeing optimal operation and safe provision of hydrocarbon and geothermal resources from the pay zone to surface facilities. Throughout the life cycle of a well, high–temperature/high–pressure changes in addition to shut–in cyclic periods can lead to strong variations in thermal and mechanical load on the well architecture. The current procedures to evaluate cement quality and to measure downhole temperature are mainly dependent on wireline–logging campaigns. In this paper, we investigate the application of the fiber–optic distributed–acoustic–sensing (DAS) technology to acquire dynamic axial–strain changes caused by propagating elastic waves along the wellbore structure. The signals are recorded by a permanently installed fiber–optic cable and are studied for the possibility of real–time well–integrity monitoring. The fiber–optic cable was installed along the 18⅝–in. anchor casing and the 21–in.–hole section of a geothermal well in Iceland. During cementing operations, temperature was continuously measured using distributed–temperature–sensing (DTS) technology to monitor the cement placement. DAS data were acquired continuously for 9 days during drilling and injection testing of the reservoir interval in the 12¼–in. openhole section. The DAS data were used to calculate average–axial–strain–rate profiles during different operations on the drillsite. Signals recorded along the optical fiber result from elastic deformation caused by mechanical energy applied from inside (e.g., pressure fluctuations, drilling activities) or outside (e.g., seismic signals) of the well. The results indicate that the average–axial–strain rate of a fiber–optic cable installed behind a casing string generates trends similar to those of a conventional cement–bond log (CBL). The obtained trends along well depth therefore indicate that DAS data acquired during different drilling and testing operations can be used to monitor the mechanical coupling between cemented casing strings and the surrounding formations, hence the cement integrity. The potential use of DTS and DAS technology in downhole evaluations would extend the portfolio to monitor and evaluate qualitatively in real time cement–integrity changes without the necessity of executing costly well–intervention programs throughout the well's life cycle.

Direction Estimation of Water-Entry Point with Single Vector Sensor

2013 ◽  
Vol 321-324 ◽  
pp. 641-644
Author(s):  
Di Xiao ◽  
Lan Yue Zhang
Keyword(s):  
Time Domain ◽  
Sound Field ◽  
Sound Intensity ◽  
Water Entry ◽  
Entry Point ◽  
Complex Sound ◽  
Simulating Experiment ◽  
Vector Sensor ◽  
Information Collecting ◽  
Vector Signal

The water-entry point was the first information collecting point on detecting an object which was dropped into water from air. Single vector sensor could estimate the direction of the water-entry point with its sound field pressure and particle velocity signals. The complex sound intensity method was applied in vector signal processing. The simulating experiment and the practical experiment on the lake were all based on the estimation deviation of the theory on different SNR. By processing the devided signal in time domain with this theory, the water-entry object could be tracing timely.

First Abu Dhabi 9.625in × 12.25in Non-Directional Casing While Drilling CWD Run for Intermediate Hole Section Saves Two Days Rig Time, Enhancing Drilling Efficiency & Improving Well Integrity

2021 ◽  
Author(s):  
Felix Leonardo Castillo ◽  
Roswall Enrique Bethancourt ◽  
Mohammed Sarhan ◽  
Abd Al Sayfi ◽  
Imad Al Hamlawi ◽  
...  
Keyword(s):  
Performance Optimization ◽  
Cost Savings ◽  
Polycrystalline Diamond ◽  
Construction Cost ◽  
Drill String ◽  
Abu Dhabi ◽  
Wellbore Instability ◽  
Well Integrity ◽  
Well Design ◽  
Cement Integrity

Abstract Significant mud losses during drilling often compromises well integrity whenever sustainable annular pressure (SAP), is observed due to poor cement integrity around 9-5/8-in casing in wells requiring gas lift completion. Heavy Casing Design (HCD) is applied as a solution; whereby, two casing strings are used to isolate the aquifers and loss zones, thus ensuring improved cement integrity around the 9 5/8-in intermediate casing. Casing While Drilling (CWD) is a potential solution to mitigate mud losses and wellbore instability enabling an optimized alternative to HCD by ensuring well integrity is maintained while reducing well construction cost. This paper details the first 12 ¼-in × 9-5/8-in non-directional CWD trial accomplished in Abu Dhabi onshore The Non-Directional CWD Technology was tested in a vertical intermediate hole section of a modified heavy casing design (MHCD) aimed at reducing well construction cost over heavy casing design (HCD) as shown in the figure 1. A drillable alloy bit with an optimized polycrystalline diamond cutters (PDC) cutting structure was used to drill with casing through a multi-formation interval with varying hardness and mechanical properties. Drilling dynamics, hydraulics and casing centralization analysis were performed to evaluate the directional tendency of the drill string along with the optimum drilling parameters to address the losses scenario, hole cleaning, vibration, and maximum surface torque. The CWD operation was completed in a single run with zero quality, health, safety, and environment (HSE) events and minimum exposure of personal to manual handling of heavy tubulars. Exceptional cement bonding was observed around the 9 5/8 in casing indicative of good hole quality despite running a significant number of centralizers (with smaller diameter), compared with the conventional drilled wells (cement bond logging was done after the section). CWD implementation saved two days of rig operations time relative to the average of the offset wells with the same casing design. The rate of Penetration (ROP) was slightly lower than the conventional drilling ROP in this application. The cost savings are mainly attributed to the elimination of casing-running flat time and Non-Productive Time (NPT) associated with clearing tight spots, BHA pack-off, wiper trips. The application of CWD in the MHCD wells deliver an estimated saving of USD 0.8MM in well construction cost per well compared to the HCD well design. Additional performance optimization opportunities have been identified for implementation in future applications. The combination of the MHCD and CWD technology enhances cementing quality across heavy loss zones translating into improved well integrity. Implementing this technology on MHCD wells could potentially save up to USD 200MM (considering 250 wells drilled). This is the first application of the technology in Abu Dhabi and brings key learning for future enhancement of drilling efficiency. The CWD technology has potential to enhance the wellbore construction process, which are typically impacted by either circulation losses and wellbore instability issues or a combination of both, it can applied to most of the offshore and onshore fields in Abu Dhabi.

Lead Application to Cure Sap Wells by Deploying Straddle Packer, Success Story

2021 ◽  
Author(s):  
Abdelrahman Mohamed Gadelhak ◽  
Mohamed Al-Badi ◽  
Ahmed Al-Bairaq ◽  
Eissa Al Mheiri ◽  
Abdullah Haj Al-Hosani ◽  
...  
Keyword(s):  
Integrity Test ◽  
Gas Well ◽  
Well Production ◽  
Electric Line ◽  
Well Integrity ◽  
Anchoring System ◽  
The Right ◽  
Alternative Solutions ◽  
Side Pocket ◽  
Integrity Issue

Abstract Objective/Scope The Increase of inactive wells due to subsurface integrity issue is observed in brown fields, Fig-1 is, showing the record for onshore UAE asset, the economic challenges is calling for alternative solutions to restore well integrity with lower cost. Straddle packer application is consists of two tandom packers with spacer pipe in between with anchoring system deployed riglessly in the well to isolate the communication point between Ann A and Tubing.Fig-2, Methods, Procedures, Process Communication between tubing and annulus A (Failure of primary barrier) is identified as the right candidate wells for straddle packer application, First step is to clearly identify the point of communication, it has been done by annulus pressure investigation excersize during flowing and shut in condition, observing the return of annulus fluid which was the same produced gas Noise log has been conducted and clearly identified the communication point at SPM (Side Pocket Mandrel) to be used for emergency killing, Tubing integrity test was conducted using nippless plugs and inflow test below and above the leak point and confirm no other leak points within the tubing Engineering drawing for the leaking assembly was reviewed to design the dimension of straddle packer assembly, length and packer size It is recommended to deploy the assembly using electric line correlation for accurate depth selection After setting annulus pressure observed no build up Well opened safely to production Results/Observation/Conclusion Leak point arrested, well primary barrier restored Removed from DWS (drilling and workover schedule) and restore well production in addition to improving inactive string KPI for Gas asset Save almost work over cost for gas well XX-197 Novel/ Additive information The way forward is to check the scalability of extending this application among other ADNOC assets and to screen the right candidate wells for this application To add this application as a part of well integrity procedures and recommendations for such like cases

Successful Hydraulic Isolation Assessment Saves Rig Utilization Time and Unnecessary Cement Remedial Squeeze Operation - Case Study, Kuwait

2021 ◽  
Author(s):  
Mohamed Elyas ◽  
Daniel Agustin Freile ◽  
Maciej Pawlowski ◽  
Larisa Tagarieva ◽  
Shamseldin Zakrya Elaila ◽  
...  
Keyword(s):  
Water Movement ◽  
Oxygen Activation ◽  
Light Weight ◽  
Bond Quality ◽  
Well Integrity ◽  
Remedial Intervention ◽  
Marginal Gain ◽  
Water Cut ◽  
The Right ◽  
Utilization Time

Abstract While drilling an 8 1/2-incli section of a north Kuwait producer well, severe mud losses were encountered. Hence, it was decided to design a light weight cement for the 7-inch liner section to avoid further losses while pumping the slurry. The main objective was to achieve a hydraulic isolation to avoid any heavy remedial intervention and potential dump flood behind the liner from the high-pressure Lower Burgan (LB) to Shuaiba. Full suite of well integrity logs were ran to properly assess whether enough hydraulic isolation was in place. To evaluate the bonding quality of the cement, two independent measurements were carried out across the 7-inch liner with the ultrasonic and sonic bond logs. A subsequent temperature survey was recorded to determine any geothermal anomaly, which could be indicative of fluid movement behind the casing. Finally, oxygen activation stations were conducted based on the cement log and temperature surveys to assure no water movement behind the casing. The ultrasonic and sonic bond log measurements showed an acceptable bond quality generally. However, the top part of Shuaiba formation up to LB exhibited relatively lower bond quality. The subsequent temperature and oxygen activation logs indicated that the zonal hydraulic isolation was achieved by showing no water movement behind the 7-inch liner. The two complementary surveys helped to take the proper forward decision for this well to go ahead with the planned perforation without cement remedial squeeze, since enough hydraulic isolation was proved to be in place behind the 7-inch liner. Additionally, this saved the rig utilization time and cost by avoiding unnecessary remedial operation. This is usually a heavy-duty operation, which takes time and induces holes in the casing that should be avoided, knowing this type of operation only provides a very marginal gain in terms of isolation. Furthermore, the well is currently producing at 0% water cut after completion. The proper cement design using light weight cement and optimized casing-landing plan were crucial to achieve good cement placement against formation. The use of the right well integrity approach helped to confirm that effective hydraulic isolation was achieved. Hence all these efforts resulted in the saved rig utilization time and cost by avoiding unnecessary squeeze intervention.

Comparison of Acrylamide and Agar Gels by Freeze-Etching

1977 ◽  
Vol 35 ◽  
pp. 606-607
Author(s):  
Russell L. Steere ◽  
Eric F. Erbe
Keyword(s):  
Electron Microscope ◽  
Sodium Hydroxide ◽  
Sodium Hypochlorite ◽  
Chromic Acid ◽  
Distilled Water ◽  
Thin Sheets ◽  
Acid Cleaning ◽  
Agar Gels ◽  
Freeze Etching ◽  
Water Cut

Thin sheets of acrylamide and agar gels of different concentrations were prepared and washed in distilled water, cut into pieces of appropriate size to fit into complementary freeze-etch specimen holders (1) and rapidly frozen. Freeze-etching was accomplished in a modified Denton DFE-2 freeze-etch unit on a DV-503 vacuum evaporator.* All samples were etched for 10 min. at -98°C then re-cooled to -150°C for deposition of Pt-C shadow- and C replica-films. Acrylamide gels were dissolved in Chlorox (5.251 sodium hypochlorite) containing 101 sodium hydroxide, whereas agar gels dissolved rapidly in the commonly used chromic acid cleaning solutions. Replicas were picked up on grids with thin Foimvar support films and stereo electron micrographs were obtained with a JEM-100 B electron microscope equipped with a 60° goniometer stage.Characteristic differences between gels of different concentrations (Figs. 1 and 2) were sufficiently pronounced to convince us that the structures observed are real and not the result of freezing artifacts.

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