Automated Intelligent Alarms to Monitoring and Identify Liquid Loading Challenge for Giant Depletion Gas Condensate Fields

2021 ◽  
Author(s):  
Ayesha Ahmed Abdulla Salem Alsaeedi ◽  
Manar Maher Mohamed Elabrashy ◽  
Mohamed Ali Alzeyoudi ◽  
Mohamed Mubarak Albadi ◽  
Sandeep Soni ◽  
...  

Abstract Depleted well monitoring is a crucial task to ensure continuous production without facing substantial issues that withhold the production, such as liquid loading. Utilizing an integrated digital production system and custom intelligence alarms functionality can help identify and analyze this bottleneck using physics-based model estimations that can help users take preventive actions, leading to saving cost, time, and effort. This paper demonstrates the identification of the liquid loading using custom intelligence alarms and an automated framework. Initially, a representative compositional well model is added to the digital twin solution enabling the automated well analysis workflow. Subsequently, custom intelligence alarms guidelines are configured to keep the well's performance and production rates under supervision with a notification capability when parameters violate the guidelines. Along with various well performance parameters being analyzed, two critical parameters for liquid loading debottlenecking, critical unloading velocity and the In-situ velocity, are investigated in the system for each well as the function of depth along well's completion. Moreover, advanced dashboards report the analysis output in an informative manner, guide users’ engineering judgment to take preventive decisions. As a result of the custom intelligence alarm, gas condensate wells suffering from liquid loading were predicted and identified. Based on the production parameter and target monitoring, these wells were unable to produce their expected mandate resulting in violating the set of production parameters guidelines. Identified wells were run through production gas rate sensitivity analysis using the analytical tool, and in conclusion, the optimal production rate was calculated. Producing the well below this critical rate causes the In-situ velocity to drop below critical unloading velocity. Additionally, using the tuned and calibrated network model, the operating choke was identified to maintain the stable flow in the well and avoid further liquid loading. This choke size was provided to field operation for implementation and saved the cost and man-hour spent during the flowing gradient surveys. The case study demonstrates significant production improvements observed for these wells, thereby significantly reducing cost and time. Using the integration of the latest production optimization platforms and custom intelligence alarm provides tools to identify wells that are currently experiencing liquid loading challenges and healthy wells that might come under the liquid loading category in the course of production, thus helping in taking proactive remedial action. Furthermore, the integrated framework provides erosional velocity-related data, which acts as a guideline while optimizing gas production.

2020 ◽  
Vol 38 (5) ◽  
pp. 1387-1408
Author(s):  
Yang Chen ◽  
Dameng Liu ◽  
Yidong Cai ◽  
Jingjie Yao

Hydraulic fracturing has been widely used in low permeability coalbed methane reservoirs to enhance gas production. To better evaluate the hydraulic fracturing curve and its effect on gas productivity, geological and engineering data of 265 development coalbed methane wells and 14 appraisal coalbed methane wells in the Zhengzhuang block were investigated. Based on the regional geologic research and statistical analysis, the microseismic monitoring results, in-situ stress parameters, and gas productivity were synthetically evaluated. The results show that hydraulic fracturing curves can be divided into four types (descending type, stable type, wavy type, and ascending type) according to the fracturing pressure and fracture morphology, and the distributions of different type curves have direct relationship with geological structure. The vertical in-situ stress is greater than the closure stress in the Zhengzhuang block, but there is anomaly in the aggregation areas of the wavy and ascending fracturing curves, which is the main reason for the development of multi-directional propagated fractures. The fracture azimuth is consistent with the regional maximum principle in-situ stress direction (NE–NEE direction). Furthermore, the 265 fracturing curves indicate that the coalbed methane wells owned descending, and stable-type fracturing curves possibly have better fracturing effect considering the propagation pressure gradient (FP) and instantaneous shut-in pressure (PISI). Two fracturing-productivity patterns are summarized according to 61 continuous production wells with different fracturing type and their plane distribution, which indicates that the fracturing effect of different fracturing curve follows the pattern: descending type > stable type > wavy type > ascending type.


2021 ◽  
Author(s):  
Jiang Wei Bo ◽  
Beryl Audrey ◽  
Uzezi Orivri ◽  
Nian Xi Wang ◽  
Xiang Yang Qiao ◽  
...  

Abstract Gas field C is an unconventional tight gas reservoir located in the central of China which has prominent characteristics, including thin formation, low permeability and poor reservoir connectivity which significantly impact on the field development. Horizontal wells multistage hydraulic fracturing has been proven to be an effective technique to recover the hydrocarbons from this gas field. However, with continuous production overtime, reservoir pressure declines which results in a decrease in gas production rate below the critical gas velocity, leading to accumulation of liquid in the wellbore (liquid loading), which further results in back pressure and damage to the formation. Currently, gas field C loses up to 1500 mmscf/year in gas production and associated revenue due to liquid loading. Some other factors which hinders effective deliquification of the gas wells include remote well pad locations, poor road conditions during harsh weather conditions, friction with local communities, limited manpower to daily effectively analyze over 200 wells for liquid loading diagnostics and operational risks during well intervention. To tackle these challenges, a new versatile intelligent dosing technology has been piloted to reduce liquid loading. This remote-control dosing unit is located at the well pad and is equipped with automatic valves that can dispense two different chemicals (soap and methanol) in one unit. A key new feature of this system is the ability to receive and implement instructions that optimizes the dosing rate and frequency. This remote-control functionality eliminates on-site operator intervention and HSE risks especially in winter when the well pads could be inaccessible with poor road conditions.


2019 ◽  
Author(s):  
Mohammed Bashir Abdullahi ◽  
A. D. I Sulaiman ◽  
Usman Abdulkadir ◽  
Ibraheem Salaudeen ◽  
Bashir Umar Shehu

2020 ◽  
Author(s):  
Reem Alsadoun ◽  
Mohammad Al Momen ◽  
Hongtao Luo

Abstract All producing wells experience reservoir pressure depletion which will ultimately cause production to cease. However, the accumulation of wellbore liquid known as liquid loading can reduce production at a faster rate bringing forward the end of well life. In theory, there are many works written on liquid loading in unconventional wells however, these assumptions are challenged when implemented in the field. The aim of this paper is to investigate the relationship between empirical and mechanistic methods used to determine liquid loading critical rates for volatile oil and gas condensate wells, improving liquid loading forecast workflow for future wells. The study was carried on a wide Pressure, Volume, and Temperature (PVT) window with varying compositions ranging from gas condensate to volatile oils. Wells with liquid loading exhibit sharp drops and fluctuations in production. Due to the wide variation in composition however, correlations used must be varied whilst accounting for both composition and horizontal configuration of the well. Using Nodal Analysis methods, Inflow Performance Relationships (IPR) and Vertical Lift Profile (VLP) curves were created from different correlation models fitted for multiple wells selected for this study to optimize well performance. By combining theoretical analysis and field practices for estimating liquid loading critical rate, the appropriate workflow was determined for the volatile oil and gas condensate wells. When comparing the critical rate for liquid loading calculated from theoretical methods against actual rates seen in the field, an inconsistency was observed between the two values for several wells. By establishing a relationship between field estimate and theoretical calculations, liquid loading was forecasted with greater certainty for varying PVT windows. When the liquid loading rate is determined earlier on, the production efficiency can be improved by deploying unloading measures, increasing the well’s producing life, and ultimately alleviating economic losses. By investigating, we were able to establish a suitable process to predict liquid loading critical rates for volatile oil and gas condensate wells. This workflow can be utilized by production engineers to arrange for liquid loading mitigation increasing well life and improving well economics.


2021 ◽  
Author(s):  
Harshil Saradva ◽  
Siddharth Jain ◽  
Christna Golaco ◽  
Armando Guillen ◽  
Kapil Kumar Thakur

Abstract Sharjah National Oil Corporation (SNOC) operates 4 onshore fields the largest of which has been in production since the 1980's. The majority of wells in the biggest field have a complex network of multilaterals drilled using an underbalanced coiled tubing technique for production enhancement in early 2000s. The scope of this project was to maximize the productivity from these wells in the late life by modelling the dynamic flow behaviour in a simulator and putting that theory to the test by recompleting the wells. A comprehensive multilateral wellbore flow study was undertaken using dynamic multiphase flow simulator to predict the expected improvement in well deliverability of these mature wells, each having 4-6 laterals (Saradva et al. 2019). The well laterals have openhole fishbone completions with one parent lateral having subsequent numerous sub-laterals reaching further into the reservoir with each lateral between 500-2000ft drilled to maximize the intersection with fractures. Complexity in simulation further increased due to complex geology, compositional simulation, condensate banking and liquid loading with the reservoir pressure less than 10% of original. The theory that increasing wellbore diameter by removing the tubing reduces frictional pressure loss was put to test on 2 pilot wells in the 2020-21 workover campaign. The results obtained from the simulator and the actual production increment in the well aligned within 10% accuracy. A production gain of 20-30% was observed on both the wells and results are part of a dynamic simulation predicting well performance over their remaining life. Given the uncertainties in the current PVT, lateral contribution and the fluid production ratios, a broad range sensitivity was performed to ensure a wide range of applicability of the study. This instils confidence in the multiphase transient simulator for subsurface modelling and the workflow will now be used to expand the applicability to other well candidates on a field level. This will result in the opportunity to maximize the production and net revenues from these gas wells by reducing the impact of liquid loading. This paper discusses the detailed comparison of the actual well behaviour with the simulation outcomes which are counterproductive to the conventional gas well development theory of utilizing velocity strings to reduce liquid loading. Two key outcomes from the project are observed, the first is that liquid loading in multilaterals is successfully modelled in a dynamic multiphase transient simulator instead of a typical nodal analysis package, all validated from a field pilot. The second is the alternative to the conventional theory of using smaller tubing sizes to alleviate gas wells liquid loading, that high velocity achieved through wellhead compression would allow higher productivity than a velocity string in low pressure late life gas condensate wells.


2020 ◽  
Author(s):  
Ayesha Ahmed Abdulla Salem Alsaeedi ◽  
Fahed Ahmed AlHarethi ◽  
Manar Maher Mohamed Elabrashy ◽  
Shemaisa Ahmed Abdalla Mohamad Alsenaidi ◽  
Nagaraju Reddicharla ◽  
...  

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