First Permanent Inflow Monitoring Experience in a Smart-Liner, Intelligent-Completion, Multi-Lateral Adnoc Offshore Well

2021 ◽  
Author(s):  
Fadwa El Maimouni ◽  
Omar Mirza ◽  
Abdelkader Aissaoui ◽  
Shawn Almstrong ◽  
Yann Bigno ◽  
...  
Keyword(s):  
Steady State ◽  
History Matching ◽  
Management Practices ◽  
Porous Polymer ◽  
Flow Profile ◽  
Chemical Tracers ◽  
Personnel Costs ◽  
Well Completion ◽  
Limited Entry ◽  
Inflow Performance

Abstract The scope of this paper is to share a field experience with permanent inflow tracer deployment and monitoring of an intelligent multi-lateral well, completed with Smart-Liner (Limited Entry Liner). It will describe what ADNOC Offshore has learnt through inflow tracing clean up surveillance from several restarts and steady state production through inflow modelling interpretation techniques. This passive method of permanent monitoring technology utilizes chemistry and materials expertise to design tracers that release signature responses when they come into contact with either in-situ oil or formation water. The chemical tracer technology enables wireless monitoring capabilities for up to five years. Unique chemical tracers are embedded in porous polymer matrix inside tracer carriers along select locations in the lower completion to correlate where the oil and water is flowing in a production well. Interpreting tracer signals can provide zonal rate information by inducing transients to create tracer signals that are transported by flow to surface and captured in sample bottles for analysis. The measured signals are matched with models through history matching to yield zonal rate estimates. ADNOC Offshore has installed inflow tracers in an intelligent multi-lateral well to monitor laterals’ contributions, to verify new completion technology, and to estimate the flow profile from individual sections of Smart-Liner, run for the first time in the field. The interpretation results have been able to characterize inflow performance without any intervention in the well. Several restart and steady state surveys are planned to understand some key characteristics of the well completion and reveal how the well has changed since it was put on production. This technology will help allocate commingled production to the three laterals. The use of inflow tracers will provide multiple inflow surveys that will reduce operational risk, well site personnel, costs and will improve reservoir management practices. Permanent inflow tracing is expected to change the way production monitoring can be performed, especially in advanced wells where PLTs or Fiber Optic technology cannot access multi-laterals.

A steady-state N balance approach for sustainable smallholder farming

2021 ◽  
Vol 118 (39) ◽  
pp. e2106576118
Author(s):  
Yulong Yin ◽  
Rongfang Zhao ◽  
Yi Yang ◽  
Qingfeng Meng ◽  
Hao Ying ◽  
...  
Keyword(s):  
Steady State ◽  
Management Practices ◽  
Global Climate ◽  
N Balance ◽  
Smallholder Farming ◽  
N Losses ◽  
Application Range ◽  
High Yields ◽  
N Management ◽  
On Farm

Hundreds of millions of smallholders in emerging countries substantially overuse nitrogen (N) fertilizers, driving local environmental pollution and global climate change. Despite local demonstration-scale successes, widespread mobilization of smallholders to adopt precise N management practices remains a challenge, largely due to associated high costs and complicated sampling and calculations. Here, we propose a long-term steady-state N balance (SSNB) approach without these complications that is suitable for sustainable smallholder farming. The hypothesis underpinning the concept of SSNB is that an intensively cultivated soil–crop system with excessive N inputs and high N losses can be transformed into a steady-state system with minimal losses while maintaining high yields. Based on SSNB, we estimate the optimized N application range across 3,824 crop counties for the three staple crops in China. We evaluated SSNB first in ca. 18,000 researcher-managed on-farm trials followed by testing in on-farm trials with 13,760 smallholders who applied SSNB-optimized N rates under the guidance of local extension staff. Results showed that SSNB could significantly reduce N fertilizer use by 21 to 28% while maintaining or increasing yields by 6 to 7%, compared to current smallholder practices. The SSNB approach could become an effective tool contributing to the global N sustainability of smallholder agriculture.

Artificial Intelligence Coreflooding Simulator for Special Core Data Analysis

2021 ◽  
pp. 1-29
Author(s):  
Eric Sonny Mathew ◽  
Moussa Tembely ◽  
Waleed AlAmeri ◽  
Emad W. Al-Shalabi ◽  
Abdul Ravoof Shaik
Keyword(s):  
Artificial Intelligence ◽  
Steady State ◽  
History Matching ◽  
Water Saturation ◽  
Flow Behavior ◽  
Model Performance ◽  
Analysis Data ◽  
Coefficient Of Determination ◽  
Water Drainage ◽  
Data Set

Two of the most critical properties for multiphase flow in a reservoir are relative permeability (Kr) and capillary pressure (Pc). To determine these parameters, careful interpretation of coreflooding and centrifuge experiments is necessary. In this work, a machine learning (ML) technique was incorporated to assist in the determination of these parameters quickly and synchronously for steady-state drainage coreflooding experiments. A state-of-the-art framework was developed in which a large database of Kr and Pc curves was generated based on existing mathematical models. This database was used to perform thousands of coreflood simulation runs representing oil-water drainage steady-state experiments. The results obtained from the corefloods including pressure drop and water saturation profile, along with other conventional core analysis data, were fed as features into the ML model. The entire data set was split into 70% for training, 15% for validation, and the remaining 15% for the blind testing of the model. The 70% of the data set for training teaches the model to capture fluid flow behavior inside the core, and then 15% of the data set was used to validate the trained model and to optimize the hyperparameters of the ML algorithm. The remaining 15% of the data set was used for testing the model and assessing the model performance scores. In addition, K-fold split technique was used to split the 15% testing data set to provide an unbiased estimate of the final model performance. The trained/tested model was thereby used to estimate Kr and Pc curves based on available experimental results. The values of the coefficient of determination (R2) were used to assess the accuracy and efficiency of the developed model. The respective crossplots indicate that the model is capable of making accurate predictions with an error percentage of less than 2% on history matching experimental data. This implies that the artificial-intelligence- (AI-) based model is capable of determining Kr and Pc curves. The present work could be an alternative approach to existing methods for interpreting Kr and Pc curves. In addition, the ML model can be adapted to produce results that include multiple options for Kr and Pc curves from which the best solution can be determined using engineering judgment. This is unlike solutions from some of the existing commercial codes, which usually provide only a single solution. The model currently focuses on the prediction of Kr and Pc curves for drainage steady-state experiments; however, the work can be extended to capture the imbibition cycle as well.

Optimization of Coal Seam Connectivity via Multi-Seam Pinpoint Fracturing Operations in the Walloons Coal Measures, Surat Basin

2021 ◽  
Author(s):  
Vibhas J. Pandey ◽  
Sameer Ganpule ◽  
Steven Dewar
Keyword(s):  
Coal Seam ◽  
History Matching ◽  
Design Matrix ◽  
Coal Seams ◽  
Major Step ◽  
Well Completion ◽  
Eastern Australia ◽  
Treatment Designs ◽  
Coal Measures ◽  
Gas Bearing

Abstract The Walloons coal measures located in Surat Basin (eastern Australia) is a well-known coal seam gas play that has been under production for several years. The well completion in this play is primarily driven by coal permeability which varies from 1 Darcy or more in regions with significant natural fractures to less than 1md in areas with underdeveloped cleat networks. For an economic development of the latter, fracturing treatment designs that effectively stimulate numerous and often thin coals seams, and enhance inter-seam connectivity, are a clear choice. Fracture stimulation of Surat basin coals however has its own challenges given their unique geologic and geomechanical features that include (a) low net to gross ratio of ~0.1 in nearly 300 m (984.3 ft) of gross interval, (b) on average 60 seams per well ranging from 0.4 m to 3 m in thickness, (c) non-gas bearing and reactive interburden, and (d) stress regimes that vary as a function of depth. To address these challenges, low rate, low viscosity, and high proppant concentration coiled tubing (CT) conveyed pinpoint stimulation methods were introduced basin-wide after successful technology pilots in 2015 (Pandey and Flottmann 2015). This novel stimulation technique led to noticeable improvements in the well performance, but also highlighted the areas that could be improved – especially stage spacing and standoff, perforation strategy, and number of stages, all aimed at maximizing coal coverage during well stimulation. This paper summarizes the findings from a 6-well multi-stage stimulation pilot aimed at studying fracture geometries to improve standoff efficiency and maximizing coal connectivity amongst various coal seams of Walloons coal package. In the design matrix that targeted shallow (300 to 600 m) gas-bearing coal seams, the stimulation treatments varied in volume, injection rate, proppant concentration, fluid type, perforation spacing, and standoff between adjacent stages. Treatment designs were simulated using a field-data calibrated, log-based stress model. After necessary adjustments in the field, the treatments were pumped down the CT at injection rates ranging from 12 to 16 bbl/min (0.032 to 0.042 m3/s). Post-stimulation modeling and history-matching using numerical simulators showed the dependence of fracture growth not only on pumping parameters, but also on depth. Shallower stages showed a strong propensity of limited growth which was corroborated by additional field measurements and previous work in the field (Kirk-Burnnand et al. 2015). These and other such observations led to revision of early guidelines on standoff and was considered a major step that now enabled a cost-effective inclusion of additional coal seams in the stimulation program. The learnings from the pilot study were implemented on development wells and can potentially also serve as a template for similar pinpoint completions worldwide.

Steady-State Flow Capacity of Wells With Limited Entry to Flow

1968 ◽  
Vol 8 (01) ◽  
pp. 43-51 ◽  
Author(s):  
A.S. Odeh
Keyword(s):  
Steady State ◽  
Open Interval ◽  
Central Portion ◽  
Formation Damage ◽  
Steady State Flow ◽  
Pressure Buildup ◽  
Slightly Compressible ◽  
State Flow ◽  
Limited Entry ◽  
Several Intervals

Abstract This paper analyzes the effect of limited entry to flow at the wellbore on the steady-state productivity of a well. Wells that have been opened to flow along a fraction of their productive interval are termed wells with limited entry. Previous work treated the cases of a partially penetrating well, a well producing from the central Portion of the productive interval and a well in which several intervals equally spaced were open to flow. In this paper the open interval can be located anywhere within the productive interval. Thus, in a sense, it generalizes previous work. The finite cosine transform was used to arrive at a solution for steady-state flow of a slightly compressible fluid. The solution was programmed for a CDC 1604 computer. Numerical values for rd = 660 ft, rw = 1/4 ft, and range of sand thickness of 20 to 200 ft are presented in graphical form. The effect of rd and rw values on the result is shown in a table. The correct calculation of skin and damage ratio in the presence of limited entry to flow is explained and illustrated by examples. Moreover, the paper shows bow to calculate the net decrease in productivity due to the combined effect of limited entry and perforations. Introduction In some wells only a fraction of the productive interval is open to flow. Location of this fraction is usually dictated by formation characteristics and reservoir behavior. For instance, if a gas cap exists, the open interval is located away from the gas-oil contact to prevent any possible gas coning. Wells that intentionally have been opened to flow along a fraction of their productive formation are termed wells with limited entry. Obviously, unintentional completions of this type also exist. Limited entry to flow decreases well productivity. Magnitude of the loss depends on the fraction of the formation open to flow, on the thickness of the sand, on the location of the open interval and on the ratio of rd/rw, where rw is well radius and rd is the drainage radius of the well. The use of pressure buildup data on producing wells to calculate the condition of the formation around the wellbore is an accepted practice. van Everdingen and Hurst introduced the concept of the skin factor s considered to be due to a thin layer of different permeability immediately around the wellbore. These authors dealt with the case of a well of complete radial geometry, i.e., a well with open-hole completion that completely penetrates the formation. The presence of a low-permeability skin results in a loss of productivity, as does limited entry. Therefore, if pressure buildup data obtained on a well with limited entry are used to establish the presence or absence of skin (i.e., formation damage), and a correction is not made for this loss of productivity, the calculations would result in an erroneous skin value. They might indicate the presence of formation damage when in reality there is none, or they might indicate a value larger than the true value. This could lead to an incorrect basis for planning remedial measures. Muskat studied the problem of partially penetrating wells for the case of incompressible flow. He presented equations and figures which allow estimation of loss in productivity. Brons and Marting, using equations based on Nisle's work, studied the loss of productivity for three cases. The first was for a partially penetrating well; the second was for a well producing from only the central portion of a productive interval; and the third was for a well in which several intervals equally spaced were open to flow. Their work was for steady-state depletion-type reservoirs wherein the well radius of drainage is established and the fluid is considered to be slightly compressible. Considered in this paper is the problem of wells with limited entry in which the open intervals are located anywhere within the productive sand. SPEJ P. 43ˆ

scholarly journals Salinity and modelling of the Annaba aquifer system, North-East of Algeria

2018 ◽  
Vol 37 (1) ◽  
pp. 113-120
Author(s):  
Habiba Majour ◽  
Azzedine Hani ◽  
Larbi Djabri
Keyword(s):  
Steady State ◽  
Solute Transport ◽  
History Matching ◽  
Transport Model ◽  
Water Levels ◽  
Model Verification ◽  
Confined Aquifer ◽  
Deep Aquifer ◽  
Aquifer System ◽  
North East

Abstract The potentiometer area in the Annaba basin, covering an area of 264 km2, has declined considerably since 1995. The analysis of the chronological hydrographs (1991–2009) of the piezometric observations shows that this decline is related to about twenty years (20 years) drought that began in 1991. To synthesize hydrological data and study regional changes in aquifer interactions caused by changes in discharge, and determine the contamination of aquifers by salty intrusion in coastal areas, and making forecasts by the year 2023, a multi-layered transient model as well as a solute transport model has been developed. The groundwater flow was modelled using the finite difference method with a horizontal dimension of 500 × 500 m for the cells. The model consists of two layers, the first corresponding to the alluvial phreatic aquifer and the second to the deep confined aquifer, and is calibrated against the steady state groundwater heads recorded before 1996. Model verification was done by history matching over the period 1991–2009. Under steady-state conditions, the correspondence between simulated and observed water levels is generally good (average difference of 0.4 m). For the deep aquifer, the simulated time-series hydrographs closely match the recorded hydrographs for most of the observation wells. For the alluvial aquifer, the recorded hydrographs cover only a short time period, but they are reproduced. The model indicates that groundwater pumping induced a decrease in natural discharge, a downward leakage in most of the basin and a continual water-level decline. The model has also been applied to the analysis of recharge impact. Simulating the behaviour of the system over the period 1991–2009 without pumping indicated small changes in hydraulic head. These results show that the groundwater reservoir has a low recharge, but excellent hydraulic properties. A solute-transport model was used to study aquifer contamination from salty intrusion in coastal sectors; it was extended to the year 2023 by simulating an optimistic hypothesis that maintains present pumping until 2023. The model indicates that the head decrease of the alluvial phreatic and deep confined aquifers will be 4 m and 5 m respectively. The solute concentration in the deep confined aquifer will increase from 1 gꞏdm−3 (prior 2009) to 5 gꞏdm−3 in 2023.

INTEGRATION OF RESERVOIR AND WELL FLOW SIMULATORS FOR ANALYSIS OF HORIZONTAL WELL PERFORMANCE

2007 ◽  
Vol 47 (1) ◽  
pp. 181
Author(s):  
G. Sanchez ◽  
A. Kabir ◽  
E. Nakagawa ◽  
Y. Manolas
Keyword(s):  
Real Time ◽  
Horizontal Well ◽  
Pressure Profile ◽  
Learning System ◽  
Well Performance ◽  
Reservoir Properties ◽  
Well Completion ◽  
Real Time Analysis ◽  
Reservoir Simulator ◽  
Inflow Performance

The optimisation of a well’s performance along its life cycle demands improved understanding of processes occurring in the reservoir, near wellbore and inside the well and flow lines. With this purpose, the industry has been conducting, for several years, initiatives towards reservoirwellbore coupled simulations.This paper proposes a simple way to couple the near wellbore reservoir and the wellbore hydraulics models, which contributes to the optimisation of well completion design (before and while drilling the well) and the maximisation of the well inflow performance during production phases, with support of real-time and historical data. The ultimate goal is the development of an adaptive (self-learning) system capable of integrated, real-time analysis, decision support and control of the wells to maximise productivity and recovery factors at reservoir/field level. At the present stage, the system simulates the inflow performance based on an iterative algorithm. The algorithm links a reservoir simulator to a hydraulics simulator that describes the flow inside the wellbore. The link between both simulators is based on equalisation of flow rates and pressures so that a hydraulic balance solution of well inflow is obtained. This approach allows for full simulation of the reservoir, taking into consideration the petrophysical and reservoir properties, which is then matched with the full pressure profile along the wellbore. This process requires relatively small CPU time and provides very accurate solutions. Finally, the paper presents an application of the system for the design of a horizontal well in terms of inflow profile and oil production when the production is hydraulically balanced.

Identification of Well Completion and Hydraulic Fracturing Performance Factors of Initial Development Wells within a Tight Oil Project in West China

2015 ◽  
Author(s):  
Jing Zhang ◽  
Xu Jiangwen ◽  
Hong Jiang ◽  
Tobias Judd ◽  
Yuan Liu ◽  
...  
Keyword(s):  
Hydraulic Fracturing ◽  
Reservoir Characterization ◽  
Junggar Basin ◽  
Microseismic Monitoring ◽  
Western China ◽  
Rapid Decline ◽  
Initial Development ◽  
Chemical Tracers ◽  
Well Completion ◽  
Single Well

Abstract The early development of a systematic approach to well completion practices centralized around multistage hydraulic fracturing treatments is often the critical component to sustainable reservoir exploitation and development. Unfortunately, the exploitation of either exploratory or underdeveloped resources often has a number of issues that include the understanding of geological heterogeneity with different results observed within close proximity and the need to optimize completion techniques to offset the potential rapid decline in well productivity. For these cases, well completion and stimulation practices are of utmost importance with the optimization and evaluation of such designs to include and account for the integration of all reservoir and geomechanical parameters. Recent vertical well results from initial exploratory wells combined with single-well horizontal pilot wells has accelerated the development plans for the Jimusaer field located in the Junggar basin of western China. This field covers a surface area of 300,000 acres with the targeted reservoir being located between 2,300 to 4,255 m true vertical depth (TVD). The application of horizontal wells from multiwell pads with each well consisting of up to 23 hydraulic fracturing treatments was meant to exploit large volumes of hydrocarbon reserves that were previously thought unattainable. Operationally, the first four wells consisted of 62 hydraulic fracturing stages and were executed within a 28-day period. The project included the application of an integrated workflow including reservoir characterization along the length of the horizontal well lateral, deployment of novel multistage openhole completion techniques with dissolvable isolation technology, factory fracturing approach with all stages being monitored by microseismic monitoring, and application of chemical tracers on selected stages to identify zonal contribution during flowback and cleanup operations. This paper describes how the acquisition of crucial reservoir and fracturing data combined with operational performance can identify areas for improvement of future completions while strengthening existing ones.

Horizontal-Steam-Injection-Flow Profiling Using Fiber Optics

SPE Journal ◽  
2019 ◽  
Vol 24 (02) ◽  
pp. 431-451 ◽  
Author(s):  
M.. Shirdel ◽  
R. S. Buell ◽  
M. J. Wells ◽  
C.. Muharam ◽  
J. C. Sims
Keyword(s):  
Fiber Optics ◽  
Fiber Optic ◽  
Steam Injection ◽  
Flow Profile ◽  
Distributed Temperature Sensing ◽  
Flow Loop ◽  
Conformance Control ◽  
Well Completion ◽  
Injection Flow ◽  
Optic Systems

Summary Steam-conformance control in horizontal injectors is important for efficient reservoir-heat management in heavy-oil fields. Suboptimal conformance and nonuniform heating of the reservoir can substantially affect the economics of the field development and oil-production response and result in nonuniform steam breakthrough. To achieve the required control, it is essential to have an appropriate well-completion architecture and robust surveillance. Five fiber-optic systems, each with a unique steam-conformance-control-completion configuration, have been installed in two horizontal steam injectors to help mature steam-injection-flow profiling and conformance-control solutions. These fiber-optic systems have used custom-designed fiber-optic bundles of multimode and single-mode fibers for distributed-temperature sensing (DTS) and distributed-acoustic sensing (DAS), respectively. Fiber-optic systems were also installed in a steam-injection-test-flow loop. All the optical fibers successfully acquired data in the wells and flow loop, measuring temperature and acoustic energy. A portfolio of algorithms and signal-processing techniques was developed to interpret the DTS and DAS data for quantitative steam-injection-flow profiling. The heavily instrumented flow-loop environment was used to characterize DTS and DAS response in a design-of-experiment (DOE) matrix to improve the flow-profiling algorithms. These algorithms are dependent on independent physical principles derived from multiphase flow, thermal hydraulic models, acoustic effects, large-data-array processing, and combinations of these methods for both transient and steady-state steam flow. A high-confidence flow profile is computed using the convergence of the algorithms. The flow-profiling-algorithm results were further validated using 11 short-offset injector observation wells wells in the reservoir that confirmed steam movement near the injectors.

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