Simulation of Dynamic Filtrate Loss During the Drilling of a Horizontal Well With Fractures and Its Impact on Well Performance

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

SPE Reservoir Evaluation & Engineering ◽

10.2118/110677-pa ◽

2009 ◽

Vol 12 (06) ◽

pp. 886-897 ◽

Cited By ~ 1

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.

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Permeability and Anisotropy Determination in a Retrograde Gas Field to Assess Horizontal Well Performance

10.2118/71811-ms ◽

2001 ◽

Cited By ~ 1

Author(s):

Cosan Ayan ◽

Michael Donovan ◽

Alan S. Pitts

Keyword(s):

Horizontal Well ◽

Well Performance ◽

Gas Field

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The Effect of Well Azimuth or Don't Let Your Landman Plan Your Well Path!

10.2118/spe-173331-ms ◽

2015 ◽

Author(s):

Fen Yang ◽

Larry K. Britt ◽

Shari Dunn-Norman

Keyword(s):

Horizontal Well ◽

Oil And Gas ◽

Horizontal Wells ◽

Horizontal Stress ◽

Well Performance ◽

Gas Reservoirs ◽

Principal Stresses ◽

Lateral Direction ◽

Well Completion ◽

Stimulation Of

Abstract Since the late 1980's when Maersk published their work on multiple fracturing of horizontal wells in the Dan Field, the use of transverse multiple fractured horizontal wells has become the completion of choice and become the “industry standard” for unconventional and tight oil and tight gas reservoirs. Today approximately sixty percent of all wells drilled in the United States are drilled horizontally and nearly all of them are multiple fractured. Because a horizontal well adds additional cost and complexity to the drilling, completion, and stimulation of the well we need to fully understand anything that affects the cost and complexity. In other words, we need to understand the affects of the principal stresses, both direction and magnitude, on the drilling completion, and stimulation of these wells. However, little work has been done to address and understand the relationship between the principal stresses and the lateral direction. This paper has as its goal to fundamentally address the question, in what direction should I drill my lateral? Do I drill it in the direction of the maximum horizontal stress (longitudinal) or do I drill it in the direction of the minimum horizontal stress (transverse)? The answer to this question relates directly back to the title of this paper and please "Don't let your land man drive that decision." This paper focuses on the horizontal well's lateral direction (longitudinal or transverse fracture orientation) and how that direction influences productivity, reserves, and economics of horizontal wells. Optimization studies using a single phase fully three dimensional numeric simulator including convergent non-Darcy flow were used to highlight the importance of lateral direction as a function of reservoir permeability. These studies, conducted for both oil and gas, are used to identify the point on the permeability continuum where longitudinal wells outperform transverse wells. The simulations compare and contrast the transverse multiple fractured horizontal well to longitudinal wells based on the number of fractures and stages. Further, the effects of lateral length, fracture half-length, and fracture conductivity were investigated to see how these parameters affected the decision over lateral direction in both oil and gas reservoirs. Additionally, how does completion style affect the lateral direction? That is, how does an open hole completion compare to a cased hole completion and should the type of completion affect the decision on in what direction the lateral should be drilled? These simulation results will be used to discuss the various horizontal well completion and stimulation metrics (rate, recovery, and economics) and how the choice of metrics affects the choice of lateral direction. This paper will also show a series of field case studies to illustrate actual field comparisons in both oil and gas reservoirs of longitudinal versus transverse horizontal wells and tie these field examples and results to the numeric simulation study. This work benefits the petroleum industry by: Establishing well performance and economic based criteria as a function of permeability for drilling longitudinal or transverse horizontal wells,Integrating the reservoir objectives and geomechanic limitations into a horizontal well completion and stimulation strategy,Developing well performance and economic objectives for horizontal well direction (transverse versus longitudinal) and highlighting the incremental benefits of various completion and stimulation strategies.

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