An Examination of the Effects of Surface Data Acquisition Methods on Well Performance Evaluations and Completion Optimization

This paper will present a software that was developed to diagnose well test data. The software monitors the data, and through a series of algorithms alarms the user in case of discrepancies. This allows the user to investigate possible source of errors and correct them in real time. Several datasets from previous operations were analyzed and the basic physics governing how a certain datum depends on others were laid out. All the well test data traditionally acquired were put on a matrix, showing the dependencies between each datum and other physical properties that are available - either measured or modelled. Acceptable fluctuations in acquired data were also identified for use as tolerance limits. The software scans through the data as it is acquired and raises an alarm when the identified dependencies are broken. The software also identified which parameter is most likely causing the error. The software was built based on previous well test data and reports. Subsequently, two field trials were conducted to fine tune the algorithms and allowable data fluctuations. The process of validating the software consisted of: (1) Identifying flagged errors that should have not been flagged (dependencies set too tight); (2) identifying errors that should have been flagged and were not (dependencies set too loose); (3) improving the user interface for ease of use. The results were positive, with several improvements in the error recognition and several discrepancies flagged that would not have been caught by the naked eye. The user interface was also improved, allowing the user to clear error messages and provide input to improve the algorithm. The field trial also demonstrated that the methodology is scalable to other data acquisition plans and to more advanced analytics. The algorithms are simple, allowing the software to be implemented in all operations. More advanced algorithms are likely to depend on job specific data and parameters. Traditional data acquisition systems used during well test only present the data. Alarms trigger the user's attention only when certain defined operability limits are about to be reached. Being able to confirm that the data is cohesive during the well test prevents a loss of confidence in the results and painful post processing exercises. Moreover, given the algorithms used are based on simple physics, it is easy to deploy the software in any operation.

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Application of Geo-Engineering Integrated Technologies for Ultradeep Longmaxi Shale Gas Life Cycle Management, Sichuan Basin

Jiang¹,

Zhao²,

Peng³

et al. 2023

Day 3 Wed, March 22, 2023

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A huge variation in well performance was observed in Longmaxi shale gas wells, in Yongchuan block, Sichuan Basin. The Longmaxi shale was buried deeper than 3500 m with complex structures, in-situ stress, and natural fracture corridors, which makes well performance very uncertain. Horizontal well length was greater than 2000 m and proppant intensity was higher than 3.5 t/m. To solve these challenges in an ultradeep shale gas play, a multidisciplinary and life cycle management strategy was proposed and practiced. Initially, geology and geophysics (G&G) work using seismic data revealed the exact geological structures with folds, faults, and natural fractures. Then the study turned to 3D high-resolution geological and geomechanics modeling to identify the sweet spots and high drilling and completion risks areas. With the deep G&G understanding, the well drilling and completion design were proposed, executed, and iterated by onsite diagnosis and support to place high-quality hydraulic fractures. Finally, the production strategy was optimized to keep the flow path undamaged during its life cycle. The detailed study and post-fracture well performance indicate that the successful ultradeep shale gas development in the Longmaxi in the Sichuan Basin relies on: Placing the wells where there are fewer faults but more natural fractures Identifying the stages with high screenout and casing failure risks, thereby levering the 3D G&G model Creating the completion design by considering the screenout and casing failure risks Executing the completion design successfully by onsite diagnosis and support, leveraging on the 3D G&G model, microseismic data, and treating pressure trend Enhancing the 3D model accuracy by iterations with observation data Minimizing the propped fracture damage by adjusting the choke size during the production phase With the high-resolution quality management on well drilling, completion, and production management, the well outperformed 100% more than the neighboring wells. The geoengineering integration values were highlighted in both the in-house study and field operations, and this strategy could be duplicated to other candidates approaching their drilling, completion, and production engineering's limits under complex geological conditions.

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An Examination of the Effects of Surface Data Acquisition Methods on Well Performance Evaluations and Completion Optimization

Cited by 3 publications

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Preparing and assessing data for use in quantitative RTA

Preparing and assessing data for use in quantitative RTA

Data Analytics Software for Automatic Detection of Anomalies in Well Testing

Application of Geo-Engineering Integrated Technologies for Ultradeep Longmaxi Shale Gas Life Cycle Management, Sichuan Basin

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