Simulation of Dynamic Filtrate Loss During the Drilling of a Horizontal Well with High-Permeability Contrasts and Its Impact on Well Performance

2009 ◽  
Vol 12 (06) ◽  
pp. 886-897 ◽  
Author(s):  
Zhan Wu ◽  
Ravimadhav N. Vaidya ◽  
P.V. Suryanarayana
Keyword(s):  
Horizontal Well ◽  
Fluid Loss ◽  
Well Performance ◽  
High Permeability ◽  
Fine Grid ◽  
Loss Model ◽  
Invaded Zone ◽  
Filtrate Loss ◽  
Reservoir Simulator ◽  
The Impact

Summary In this paper, we present a new approach for modeling filtrate invasion during the drilling of a horizontal well through regions with high-permeability contrasts, such as those caused by fractures and high-permeability streaks, and the impact that the cleanup of this approach has on well performance. The approach incorporates the drilling schedule and experiment-based dynamic filtrate-loss data into a fine-grid multiphase reservoir simulator. Unlike the traditional leakoff model, which assumes piston-like displacement in the filtrate-invaded zone, fluid flow in the invaded and the reservoir zones is described by the use of more-realistic two-phase water/gas flow equations. The equations are solved under the dynamic boundary conditions of the leakoff model and time-varying reservoir exposure from drilling, tripping, completions, and work-overs. Because the impact of fractures on both invasion and flowback is more pronounced in low-permeability (tight) formations, the focus of this paper is on such formations. In overbalanced drilling, the initial dynamic mudcake formation is critical in controlling filtrate loss. A dynamic fluid-loss model, which reflects the spurt loss and non-Darcy and non-Newtonian characteristics of filtrate flow through the mudcake is coupled with the reservoir simulator. Mud properties and different events during drilling influence compression, dynamic deposition, and erosion of the mudcake. The application of the dynamic filtrate-loss model avoids the complexity in building a multiparameter mathematical mudcake model without loss of generality. As in previous work, parameters in the dynamic filtrate-loss model are based on special core tests. In existing experiments, leakoff coefficients are measured only for the matrix. The extrapolation of the dynamic leakoff coefficients for simulation of fluid loss into intersecting fractures is discussed. Driven by Buckley-Leverett equations, theoretical analysis is presented to emphasize the quantitatively spatial correlation between the invaded-filtrate saturation and the spatial permeability reduction in the invaded zone. The influence of water blocking, relative permeability alteration, and damaged permeability variation on well performance is simulated. A horizontal-well example is used to illustrate the flexibility of this approach, and the results are discussed in the context of well performance.

scholarly journals Effect of Iron Oxide Nanoparticles on the Properties of Water-Based Drilling Fluids

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6718
Author(s):  
Muhammad Awais Ashfaq Alvi ◽  
Mesfin Belayneh ◽  
Sulalit Bandyopadhyay ◽  
Mona Wetrhus Minde
Keyword(s):  
Iron Oxide ◽  
Coefficient Of Friction ◽  
Drilling Fluid ◽  
Precipitation Method ◽  
Fluid Loss ◽  
Drilling Fluids ◽  
The Coefficient Of Friction ◽  
Filtrate Loss ◽  
Co Precipitation ◽  
The Impact

In recent years, several studies have indicated the impact of nanoparticles (NPs) on various properties (such as viscosity and fluid loss) of conventional drilling fluids. Our previous study with commercial iron oxide NPs indicated the potential of using NPs to improve the properties of a laboratory bentonite-based drilling fluid without barite. In the present work, iron oxide NPs have been synthesized using the co-precipitation method. The effect of these hydrophilic NPs has been evaluated in bentonite and KCl-based drilling fluids. Rheological properties at different temperatures, viscoelastic properties, lubricity, and filtrate loss were measured to study the effect of NPs on the base fluid. Also, elemental analysis of the filtrate and microscale analysis of the filter cake was performed. Results for bentonite-based fluid showed that 0.019 wt% (0.1 g) of NPs reduced the coefficient of friction by 47%, and 0.0095 wt% (0.05 g) of NPs reduced the fluid loss by 20%. Moreover, for KCl-based fluids, 0.019 wt% (0.1 g) of additive reduced the coefficient of friction by 45%, while higher concentration of 0.038 wt% (0.2 g) of NPs shows 14% reduction in the filtrate loss. Microscale analysis shows that presence of NPs in the cake structure produces a more compact and less porous structure. This study indicates that very small concentration of NPs can provide better performance for the drilling fluids. Additionally, results from this work indicate the ability of NPs to fine-tune the properties of drilling fluids.

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.

scholarly journals A numerical reservoir simulator applicable to horizontal well performance.

1993 ◽  
Vol 58 (6) ◽  
pp. 466-473
Author(s):  
Yasunobu Watanabe ◽  
Nobuhiko Tomita ◽  
Hiroshi Ishii
Keyword(s):  
Horizontal Well ◽  
Well Performance ◽  
Reservoir Simulator

scholarly journals The Impact of Fluid Loss and Carbohydrate Consumption during Exercise, on Young Cyclists’ Fatigue Perception in Relation to Training Load Level

2021 ◽  
Vol 18 (6) ◽  
pp. 3282
Author(s):  
Leonardo Cesanelli ◽  
Berta Ylaitė ◽  
Giuseppe Messina ◽  
Daniele Zangla ◽  
Stefania Cataldi ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Wide Spectrum ◽  
Load Level ◽  
Training Load ◽  
Fluid Loss ◽  
Young Athletes ◽  
Carbohydrate Consumption ◽  
Significant Difference ◽  
Training Impulse ◽  
The Impact

High-level young athletes need to face a wide spectrum of stressors on their journey to élite categories. The aims of the present study are (i) to evaluate session rate of perceived exertion (sRPE) at different training impulse (TRIMP) categories and the correlations between these two variables and, (ii) evaluate the correlations between sRPE, fluid loss, and carbohydrate consumption during exercise. Data on Edward’s TRIMP, sRPE, body mass loss pre- and post- exercise (∆), and carbohydrate consumption (CHO/h) during exercise have been acquired from eight male junior cyclists during a competitive season. One-way ANOVA and correlation analysis with linear regression have been performed on acquired data. sRPE resulted in a significant difference in the three TRIMP categories (p < 0.001). sRPE resulted in being very largely positively associated with TRIMP values (p < 0.001; R = 0.71). ∆ as well as CHO/h was largely negatively related with sRPE in all TRIMP categories (p < 0.001). The results confirmed the role of fluid balance and carbohydrate consumption on the perception of fatigue and fatigue accumulation dynamics independently from the training load. Young athletes’ training load monitoring and nutritional-hydration support represent important aspects in athlete’s exercise-induced fatigue management.

Data-Driven Causal Analyses of Parent-Child Well Interactions for Well Spacing Decisions

2021 ◽  
Author(s):  
Rohan Sakhardande ◽  
Deepak Devegowda
Keyword(s):  
Causal Inference ◽  
Randomized Clinical Trials ◽  
Drug Efficacy ◽  
Complex Problem ◽  
Petroleum Engineering ◽  
Well Performance ◽  
Well Spacing ◽  
The Impact ◽  
Naive Approach ◽  
Parent Child

Abstract The analyses of parent-child well performance is a complex problem depending on the interplay between timing, completion design, formation properties, direct frac-hits and well spacing. Assessing the impact of well spacing on parent or child well performance is therefore challenging. A naïve approach that is purely observational does not control for completion design or formation properties and can compromise well spacing decisions and economics and perhaps, lead to non-intuitive results. By using concepts from causal inference in randomized clinical trials, we quantify the impact of well spacing decisions on parent and child well performance. The fundamental concept behind causal inference is that causality facilitates prediction; but being able to predict does not imply causality because of association between the variables. In this study, we work with a large dataset of over 3000 wells in a large oil-bearing province in Texas. The dataset includes several covariates such as completion design (proppant/fluid volumes, frac-stages, lateral length, cluster spacing, clusters/stage and others) and formation properties (mechanical and petrophysical properties) as well as downhole location. We evaluate the impact of well spacing on 6-month and 1-year cumulative oil in four groups associated with different ranges of parent-child spacing. By assessing the statistical balance between the covariates for both parent and child well groups (controlling for completion and formation properties), we estimate the causal impact of well spacing on parent and child well performance. We compare our analyses with the routine naïve approach that gives non-intuitive results. In each of the four groups associated with different ranges of parent-child well spacing, the causal workflow quantifies the production loss associated with the parent and child well. This degradation in performance is seen to decrease with increasing well spacing and we provide an optimal well spacing value for this specific multi-bench unconventional play that has been validated in the field. The naïve analyses based on simply assessing association or correlation, on the contrary, shows increasing child well degradation for increasing well spacing, which is simply not supported by the data. The routinely applied correlative analyses between the outcome (cumulative oil) and predictors (well spacing) fails simply because it does not control for variations in completion design over the years, nor does it account for variations in the formation properties. To our knowledge, there is no other paper in petroleum engineering literature that speaks of causal inference. This is a fundamental precept in medicine to assess drug efficacy by controlling for age, sex, habits and other covariates. The same workflow can easily be generalized to assess well spacing decisions and parent-child well performance across multi-generational completion designs and spatially variant formation properties.

The New Flow Control Devices Autonomously Controlling the Performance of Matrix Acid Stimulation Operations in Carbonate Reservoirs

2021 ◽  
Author(s):  
Mojtaba Moradi ◽  
Michael R Konopczynski
Keyword(s):  
Flow Control ◽  
Dynamic Change ◽  
Injection Rate ◽  
Control Flow ◽  
Carbonate Reservoir ◽  
Operating Conditions ◽  
Carbonate Reservoirs ◽  
High Permeability ◽  
The Impact ◽  
Stimulation Of

Abstract Matrix acidizing is a common but complex stimulation treatment that could significantly improve production/injection rate, particularly in carbonate reservoirs. However, the desired improvement in all zones of the well by such operation may not be achieved due to existing and/or developing reservoir heterogeneity. This paper describes how a new flow control device (FCD) previously used to control water injection in long horizontal wells can also be used to improve the conformance of acid stimulation in carbonate reservoirs. Acid stimulation of a carbonate reservoir is a positive feedback process. Acid preferentially takes the least resistant path, an area with higher permeability or low skin. Once acid reacts with the formation, the injectivity in that zone increases, resulting in further preferential injection in the stimulated zone. Over-treating a high permeability zone results in poor distribution of acid to low permeability zones. Mechanical, chemical or foam diversions have been used to improve stimulation conformance along the wellbore, however, they may fail in carbonate reservoirs with natural fractures where fracture injectivity dominates the stimulation process. A new FCD has been developed to autonomously control flow and provide mechanical diversion during matrix stimulation. Once a predefined upper limit flowrate is reached at a zone, the valve autonomously closes. This eliminates the impact of thief zone on acid injection conformance and maintains a prescribed acid distribution. Like other FCDs, this device is installed in several compartments in the wells. The device has two operating conditions, one, as a passive outflow control valve, and two, as a barrier when the flow rate through the valve exceeds a designed limit, analogous to an electrical circuit breaker. Once a zone has been sufficiently stimulated by the acid and the injection rate in that zone exceeds the device trip point, the device in that zone closes and restricts further stimulation. Acid can then flow to and stimulate other zones This process can be repeated later in well life to re-stimulate zones. This performance enables the operators to minimise the impacts of high permeability zones on the acid conformance and to autonomously react to a dynamic change in reservoirs properties, specifically the growth of wormholes. The device can be installed as part of lower completions in both injection and production wells. It can be retrofitted in existing completions or be used in a retrievable completion. This technology allows repeat stimulation of carbonate reservoirs, providing mechanical diversion without the need for coiled tubing or other complex intervention. This paper will briefly present an overview of the device performance, flow loop testing and some results from numerical modelling. The paper also discusses the completion design workflow in carbonates reservoirs.

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