The Impact of Nonuniform Formation Damage on Horizontal Well Performance

2006 ◽  
Author(s):  
Turhan Yildiz
Keyword(s):  
Horizontal Well ◽  
Formation Damage ◽  
Well Performance ◽  
The Impact

Estimation of Horizontal-Well Productivity Loss Caused by Formation Damage on the Basis of Numerical Modeling and Laboratory-Testing Data

SPE Journal ◽  
2018 ◽  
Vol 24 (01) ◽  
pp. 44-59 ◽  
Author(s):  
Dmitry D. Vodorezov
Keyword(s):  
Analytical Solutions ◽  
Laboratory Testing ◽  
Horizontal Well ◽  
Damage Zone ◽  
Formation Damage ◽  
Well Productivity ◽  
Skin Factor ◽  
Damaged Zone ◽  
Variable Distribution ◽  
The Impact

Summary This paper presents a new numerical model of inflow to a well with a zone of damaged permeability. It is built on the principle of dividing the wellbore and damaged permeability zone into numerous segments. Simultaneous work of the segments is modeled with the method of velocity-potential theory. The model is applicable for wellbores of different trajectories including horizontal and multilateral wells. The model is focused on the extended application of results obtained during laboratory core testing that include a return-permeability (RP) profile of the core and cleanup parameters. The developed solution includes the effects of anisotropy, reservoir-boundary conditions, and a nonuniform distribution of formation damage in both radial and axial directions. The paper presents the new approach to include depth-variable distribution of damage in skin-factor models. The approach provides for the evaluation of pressure drop in a depth-variable damage zone by the resulting permeability that is defined by flow regime. Laboratory-obtained overall core permeability is associated with a linear flow, and when applied to a zone near the wellbore with radial or elliptic flow, it causes an error because of the depth-variable distribution of damage. The provided numerical simulations show that the impact of this factor on horizontal-well productivity is significant. The developed model is compared with existing analytical solutions of Furui et al. (2002) (FZH) and Frick and Economides (1993) (FE) for the case of a horizontal well with a cone-shaped damaged zone. The results show that a skin-factor transformation originally proposed by Renard and Dupuy (1991) for a case of a uniformly damaged well can be used successfully for the referred-to analytical solutions, which makes them applicable for wells with an elliptic drainage area. In this paper, we also suggest an approach whereby we relate the characteristics of the cleanup of the region near the wellbore to laboratory-testing conditions.

scholarly journals FORMATION DAMAGE MECHANISMS AND NUMERICAL SIMULATION OF PERMEABILITY IMPAIRMENT IN HORIZONTAL WELLS

2021 ◽  
Vol 15 (2) ◽  
pp. 184-204
Author(s):  
Tunde Adeosun ◽  
Moruffdeen Adabanija ◽  
Folake Akinpelu
Keyword(s):  
Numerical Simulation ◽  
Linear Partial Differential Equation ◽  
Horizontal Wells ◽  
Numerical Approach ◽  
Formation Damage ◽  
Well Performance ◽  
Damage Mechanisms ◽  
Pressure Losses ◽  
Permeability Impairment ◽  
The Impact

Puzzling circumstance associated with formation damage near wellbore occur frequently, resulting in permeability impairments and increased pressure losses. Potential damage phenomenon usually starts from drilling to completion via production and such mechanisms have been fully considered. Most of the existing tasks to mitigate the near oil wellbore damages involve use of empirical models, conducting experiments, frequent shut down of wells for proper well tests and pressure maintenance are highly expensive and time consuming. Permeability impairments have been simulated by modifying Darcy’s equation to optimize reservoir pressure for improved near wellbore in horizontal wells. The model, transient linear partial differential equation (TLPDE) for impaired permeability is developed and numerically resolved using finite difference method. The model was implemented by writing codes in MATLAB language and the solution obtained was validated using synthetic/ field data. The results obtained for TLPDE model indicated pressure depletion over time. This was also shown for every values of coefficient of anisotropy until 400 days when the anisotropy became insignificant approaching isotropy condition, suggesting permeability impairment. Numerical simulation proved to be effective in simulating near oil wellbore damages. This paper describes the detailed mechanisms of formation damage and provided a numerical approach to model impaired permeability in horizontal wells. This approach allowed us to study the impact of various damage mechanisms related to drilling, completion conditions and significant improvement of near oil wellbore for well performance.

Evaluation of Horizontal Well Performance After Drilling-Induced Formation Damage

2005 ◽  
Vol 127 (3) ◽  
pp. 257-263 ◽  
Author(s):  
Y. Ding ◽  
G. Renard
Keyword(s):  
Horizontal Well ◽  
Oil And Gas ◽  
Horizontal Wells ◽  
Integrated Approach ◽  
Formation Damage ◽  
Well Performance ◽  
Wellbore Modeling ◽  
Open Hole ◽  
Testing Techniques ◽  
Study Laboratory

It is well recognized that near-wellbore formation damage can dramatically reduce well productivities, especially for open hole completed horizontal wells. The economic impact of poor productivity of these wells has pushed toward significant efforts in recent years to study laboratory testing techniques and numerical modeling methods for predicting and controlling drilling-induced formation damage. This paper presents an integrated approach, combining a near-wellbore modeling with laboratory experiments for data acquisition as input for the model, to evaluate the performance of oil and gas wells after drilling-induced formation damage.

Impact of Perforating on Well Performance and Cumulative Production

2002 ◽  
Vol 124 (3) ◽  
pp. 163-172 ◽  
Author(s):  
Turhan Yildiz
Keyword(s):  
Sensitivity Study ◽  
Formation Damage ◽  
Two Dimensional ◽  
Well Performance ◽  
Total Recovery ◽  
Well Model ◽  
Simplified Method ◽  
Cumulative Production ◽  
Inflow Performance ◽  
The Impact

This study presents a simplified method to predict inflow performance of and cumulative production from selectively perforated wells in bounded reservoirs. The model first calculates the pseudo-skin for a fully perforated well penetrating a formation with only unit thickness. Then, perforation pseudo-skin is superimposed on a two-dimensional selectively open completed well model. Using the new model, a sensitivity study is carried out to identify the parameters controlling the well flow rate and total recovery. The sensitivity study includes the impact of shot density, perforation size and length, phasing angle, perforated length/formation thickness ratio, and the degree of formation damage around the wellbore and perforations.

Impact of Delayed Flowback on Well Performance: Case Study

2022 ◽  
Author(s):  
Ruqia Al Shidhani ◽  
Ahmed Al Shueili ◽  
Hussain Al Salmi ◽  
Musallam Jaboob
Keyword(s):  
Hydraulic Fracturing ◽  
Large Scale ◽  
Gas Permeability ◽  
Real Data ◽  
Formation Damage ◽  
Single Fracture ◽  
Well Performance ◽  
Fracture Conductivity ◽  
Wellhead Pressure ◽  
The Impact

Abstract Due to a resource optimization and efficiency improvements, wells that are hydraulically fractured in the tight gas Barik Formation of the Khazzan Field in the Sultanate of Oman are often temporarily left shut-in directly following a large scale massive hydraulic fracturing stimulation treatment. Extensive industry literature has often suggested (and reported), that this may result in a significant direct loss of productivity due to the delayed flowback and the resulting fracture conductivity and formation damage. This paper will review the available data from the Khazzan Field address these concerns; indicating where the concerns should and should not necessarily apply. The Barik Formation in the Khazzan Field is an over-pressured gas-condensate reservoir at 4,500 m with gas permeability ranging from 0.1 to 20 mD. The average well after hydraulic fracturing produces 25 MMscfd and 500 bcpd against a wellhead pressure of 4,000 psi. A typical hydraulic fracturing stimulation treatment consists of 14,000 bbl of a borate-crosslinked guar fluid, placing upwards of 1MM Lbs of high conductivity bauxite proppant within a single fracture. In order to assess the potential production loss due to delayed flowback operations, BP Oman performed a suite of formation damage tests including core samples from the Barik reservoir, fracture conductivity considerations and dynamic behaviors. Additionally, normalized production was compared between offset wells that were cleaned-up and put onto production at different times after the hydraulic fracturing operations. Core tests showed a range of fracture conductivities over time with delayed flowback after using the breaker concentrations from actual treatments. As expected, enhanced conductivity was achieved with additional breaker. The magnitude of the conductivity being created in these massive treatments was also demonstrated to be dominant with respect to damage effects. Finally, a normalized comparison of an extensive suite of wells clearly showed no discernible loss of production resulted from any delay in the flowback operations. This paper describes in details the workflow and resulting analysis of the impact of extensive shut-in versus immediate flowback post massive hydraulic fracturing. It indicates that the impact of such events will be limited if the appropriate steps have been taken to minimize the opportunity for damage to occur. Whereas the existing fracturing literature takes the safe stance of indicating that damage will always result from such shut-ins, this paper will demonstrate the limitations of such assumptions and the flexibility that can be demonstrated with real data.

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.

Sign in / Sign up

Export Citation Format

Share Document