Using 3D Fracture Simulation Alone May Result in Incorrect Fracture-Geometry Determination and Unreliable Real-Time Fracture Analysis

1996 ◽  
Author(s):  
Roland E. Blauer ◽  
David L. Holcomb
Keyword(s):  
Real Time ◽  
Fracture Analysis ◽  
Fracture Geometry ◽  
Fracture Simulation

Fiber Optic Deployed Behind Cemented Casing in a Vertical Deep Tight Gas Well Used to Enhance Hydraulic Fracturing, Monitoring and Diagnostics

2021 ◽  
Author(s):  
Ahmed Rashid Al-Jahdhami ◽  
Juan Carlos Chavez ◽  
Shaima Abdul Aziz Al-Farsi
Keyword(s):  
Real Time ◽  
Surface Pressure ◽  
Hydraulic Fracture ◽  
Fiber Optic ◽  
Integrated Analysis ◽  
Radioactive Tracers ◽  
Distributed Temperature Sensing ◽  
Time Data ◽  
Fracture Geometry ◽  
Fracture Simulation

Abstract The use of fiber optic (FO) to obtain distributed sensing be it Distributed Temperature Sensing (DTS), Distributed Acoustic Sensing (DAS) or Distributed Strain Sensing (DSS) is a well & reservoir surveillance engineer's dream. The ability to obtain real-time live data has proven useful not only for production monitoring but during fracture stimulation as well. A trial the first of its kind in Petroleum Development Oman (PDO) used fiber optic cable cemented in place behind casing to monitor the fracture operations. Several techniques are used to determine fracture behaviour and geometry e.g. data fracs, step down test and after closure analysis. All these use surface pressure readings that can be limited due to uncertainty in friction pressure losses and the natural complexity in the formation leading to very different interpretations. Post frac data analysis and diagnostics also involves importing the actual frac data into the original model used to design the frac in order to calibrate the strains (tectonics), width exponent (frac fluid efficiency) and the relative permeability. Monitoring the frac using DAS and DTS proved critical in understanding a key component in fracture geometry; frac height. The traditional method to determine fracture height is to use radioactive tracers (RA). But these are expensive and the data only available after the job (after drilling the plugs and cleaning the wellbore). In contrast fiber optic can provide real time data throughout the frac stages including the proppant free PAD stage which tracers can't. The comparison of DTS and Radioactive Tracers showed very good agreement suggesting that DTS could replace RA diagnostic. Hydraulic fracture stimulation operations in well-xx was the first one of its kind to be monitored with fiber optic. The integrated analysis of the available logs allowed us to benchmark various information and gain confidence in the conclusions. This helped fine tune the model for future wells for a more optimized zonal targeting and hydraulic fracture design. In this paper we will share the detailed evaluation of the fracture propagation behaviour and how combining the fiber optic data with the surface pressure, pumping rates and tracer logs in conjunction with a fracture simulation platform where a detailed geomechanical and subsurface characterization data is incorporated to get a more accurate description of fracture geometry.

Using Real-Time Downhole Microseismic To Evaluate Fracture Geometry for Horizontal Packer-Sleeve Completions in the Bakken Formation, Elm Coulee Field, Montana

2012 ◽  
Vol 27 (01) ◽  
pp. 27-43 ◽  
Author(s):  
Darien G. O'Brien ◽  
Robert T. Larson ◽  
Ron Parham ◽  
Blane L. Thingelstad ◽  
William W. Aud ◽  
...  
Keyword(s):  
Real Time ◽  
Bakken Formation ◽  
Fracture Geometry ◽  
Elm Coulee

Experiments and simulations of a prototype triaxial electromagnetic induction logging tool for open-hole hydraulic fracture diagnostics

Geophysics ◽  
2018 ◽  
Vol 83 (3) ◽  
pp. D73-D81 ◽  
Author(s):  
Javid Shiriyev ◽  
Yaniv Brick ◽  
Peng Zhang ◽  
Ali E. Yilmaz ◽  
Carlos Torres-Verdín ◽  
...  
Keyword(s):  
Real Time ◽  
Electrically Conductive ◽  
Fracture Geometry ◽  
Induction Logging ◽  
Open Hole ◽  
Parametric Inversion ◽  
Induced Fractures ◽  
Monitoring And Diagnostics ◽  
Inversion Techniques ◽  
Logging Tool

The monitoring and diagnostics of induced fractures are important for the real-time performance evaluation of hydraulic fracturing operations. Previous electromagnetic-based studies show that single backbone triaxial induction logging tools are promising candidates for real-time monitoring and diagnosis of fractures in noncased wells. With a fast-forward solver and reliable parametric inversion techniques, it may be possible to estimate many features of the propped fracture geometry (e.g., area, dip, conductivity) from the measured induced voltages. To support the development of field deployable tools, the concept must be tested in experiments, in a controllable environment, before it is tested under field-like conditions. To this end, we have designed and built a prototype induction tool and performed two sets of tests to compare with numerical simulation results. The experimental setup consists of triaxial transmitter and receiver coils in coaxial, coplanar, and cross-polarized configurations. Thin (highly conductive) metallic targets of various sizes, shapes, and orientations are used to emulate various fracture geometries. The laboratory and shallow earth measurements are shown to be in good agreement with simulations for all examined cases. The average relative and maximum discrepancies of the measured signals from the simulated ones are lower than 3% and 10%, respectively. With the prototype tool, strong signals sensitive to the fracture’s surface area and dip are measured in a coaxial coil configuration, whereas weaker signals sensitive to the fracture’s aspect ratio are observed in a coplanar configuration. Cross-polarized signals are also shown to be strong and sensitive to the fracture’s dip. The results suggest that a tool of similar specifications can be used for the detection and extraction of the parameters of fractures propped with sufficiently electrically conductive proppant.

An Integrated Approach for Statistical Microscale Homogenization to Macroscopic Dynamic Fracture Analysis

2018 ◽  
Author(s):  
Bahador Bahmani ◽  
Ming Yang ◽  
Anand Nagarajan ◽  
Philip L. Clarke ◽  
Soheil Soghrati ◽  
...  
Keyword(s):  
Finite Element ◽  
Adaptive Mesh Refinement ◽  
Adaptive Mesh ◽  
Integrated Approach ◽  
Fracture Analysis ◽  
Uniaxial Tensile ◽  
Material Interfaces ◽  
Element Mesh ◽  
Structured Adaptive Mesh Refinement ◽  
Fracture Simulation

Maintaining material inhomogeneity and sample-to-sample variations is crucial in fracture analysis, particularly for quasibrittle materials. We use statistical volume elements (SVEs) to homogenize elastic and fracture properties of ZrB2-SiC, a two-phase composite often used for thermal coating. At the mesoscale, a 2D finite element mesh is generated from the microstructure using the Conforming to Interface Structured Adaptive Mesh Refinement (CISAMR), which is a non-iterative algorithm that tracks material interfaces and yields high-quality conforming meshes with adaptive operations. Analyzing the finite element results of the SVEs under three traction loadings, elastic and angle-dependent fracture strengths of SVEs are derived. The results demonstrate the statistical variation and the size effect behavior for elastic bulk modulus and fracture strengths. The homogenized fields are mapped to macroscopic material property fields that are used for fracture simulation of the reconstructed domain under a uniaxial tensile loading by the asynchronous Spacetime Discontinuous Galerkin (aSDG) method.

Advanced Fracturing Design Simulator-Assisted Modeling Coupled with Application of Enhanced Stimulation Fluids Raises Performance of Acid Fractured Wells

2021 ◽  
Author(s):  
Ruslan Kalabayev ◽  
Dmitriy Abdrazakov ◽  
Yeltay Juldugulov ◽  
Vladimir Stepanov ◽  
Denis Emelyanov ◽  
...  
Keyword(s):  
Single Phase ◽  
Viscous Fingering ◽  
Low Ph ◽  
Transport Processes ◽  
Carbonate Reservoirs ◽  
Productivity Index ◽  
Fracture Geometry ◽  
Acid Fracturing ◽  
Fracture Simulation ◽  
Half Length

Abstract Important factors affecting acid fracturing efficiency include etched fracture geometry, cleanup, and optimum differential etching to retain open channels after fracture closure. A recently applied integrated approach combined improvements in all three factors: new fracture simulation techniques enabled fracture geometry optimization, single-phase retarded acid provided significant increase in half-length, and high retained permeability viscous fluids supported better fracture cleanup. The approach was successfully implemented in several carbonate oil fields and resulted in a substantial productivity index increase. The approach enables acid fracture optimization in three steps. First, the high retained permeability, low-pH pad fluids and polymer-free leakoff control acids are used in combination to enhance formation cleanup after a treatment and to reduce the concentration of polymers in fissures network of naturally fractured carbonate reservoirs. Second, a new single-phase retarded acid is used to achieve longer half-length due to retarded reaction with formation rock and favorable viscous fingering effects. Third, a new acid fracturing simulation model is used to optimize fracture geometry. The simulation technique employs an innovative transport model that includes the viscous fingering effect, advanced leakoff simulation, changing acid rheology upon spending, and a novel calculation approach to mixed fluids' rheology. This combined concept was applied during acid fracturing treatments in moderate permeability wells of carbonate reservoirs with target intervals up to 4,600 m TVD and temperatures up to 125°C. The treatments consisted of guar-free low-pH pad fluid, polymer-free leakoff control acid, and single-phase retarded acid. Treatment optimization was performed using an advanced acid fracturing simulator to properly address the transport processes within the fracture in a low-stress-contrast environment. After the treatments, the pressure transient analysis indicated a strong linear regime for more than 15 hours, indicating effective fracture half-length at least 25% higher than average half-length after acid fracturing in offset wells where the conventional approach had been applied. Post-treatment half-length calculations showed a good match with advanced simulator results and proved the importance of accounting for viscous fingering effects during acid fracture half-length calculations. Calculation of the productivity index from the production data showed at least 15% increase compared to conventional acid fracturing treatments. The post-fracturing production decline rate was at least 20% slower than that of the conventional treatment in offset wells, which can be explained by the longer conductive fracture.

Using Real-Time Downhole Microseismic to Evaluate Fracture Geometry for Horizontal Packer-Sleeve Completions in the Bakken Formation, Elm Coulee Field, Montana

2011 ◽  
Author(s):  
Darien Gerard O'Brien ◽  
Robert Thomas Larson ◽  
Ron Parham ◽  
Blane Lee Thingelstad ◽  
William Wayne Aud ◽  
...  
Keyword(s):  
Real Time ◽  
Bakken Formation ◽  
Fracture Geometry ◽  
Elm Coulee

Some Recent Results in Quiescent Prominence Spectrometry

1979 ◽  
Vol 44 ◽  
pp. 41-47
Author(s):  
Donald A. Landman
Keyword(s):  
Real Time ◽  
Computer System ◽  
Spectral Response ◽  
Absolute Intensity ◽  
Solar Observatory ◽  
Target Size ◽  
Small Target ◽  
Signal Averaging ◽  
Quiescent Prominence

This paper describes some recent results of our quiescent prominence spectrometry program at the Mees Solar Observatory on Haleakala. The observations were made with the 25 cm coronagraph/coudé spectrograph system using a silicon vidicon detector. This detector consists of 500 contiguous channels covering approximately 6 or 80 Å, depending on the grating used. The instrument is interfaced to the Observatory’s PDP 11/45 computer system, and has the important advantages of wide spectral response, linearity and signal-averaging with real-time display. Its principal drawback is the relatively small target size. For the present work, the aperture was about 3″ × 5″. Absolute intensity calibrations were made by measuring quiet regions near sun center.

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