COMPREHENSIVE ANALYSIS OF DRILLSTEM TEST DATA WITH THE AID OF TYPE CURVES

1980 ◽  
Vol 20 (1) ◽  
pp. 229
Author(s):  
B.K. Sinha ◽  
J.M. Montgomery
Keyword(s):  
Test Data ◽  
Comprehensive Analysis ◽  
Insufficient Data ◽  
Type Curve ◽  
Type Curves ◽  
Correct Analysis

A substantial percentage of drillstem tests cannot be analysed by convential methods due to insufficient data. Numerous tests have been analysed by several published type curves.In this paper, many examples are included where the application of the appropriate type curve aided in providing correct analysis of data which otherwise may have been misinterpreted.

Analytical Model for Vertical Interference Tests Across Low-Permeability Zones

1985 ◽  
Vol 25 (03) ◽  
pp. 407-418 ◽  
Author(s):  
R.E. Bremer ◽  
Winston Hubert ◽  
Vela Saul
Keyword(s):  
Point Source ◽  
Test Data ◽  
Low Permeability ◽  
Test Analysis ◽  
Type Curve ◽  
Type Curves ◽  
Pulse Test ◽  
Vertical Permeability ◽  
Interference Test ◽  
Interference Tests

Abstract A mathematical model is developed that describes fluid flow and pressure behavior in a reservoir consisting of two permeable zones separated by a zone of low permeability, Or a "tight zone." This model can be used to design and to interpret buildup, vertical, interference, and pulse tests conducted in a single well or multiple wells across lithological strata. Dimensionless pressure functions and corresponding parametric type curves are derived to interpret vertical interference test data for tight-zone vertical penneability. Application of these type curves is illustrated using field data from two vertical interference tests. Test results obtained with the tight-zone model are shown to compare favorably with results obtained by usingcomputer simulations andBurns' method based on the uniform anisotropy assumption. Computer simulation using a numerical model also shows that high near-wellbore conductivity from a packer leak or poor cement job could not have adversely affected test results. The model presented and the type-curve interpretation method outlined are accurate for designing and interpreting single-well vertical interference tests across low-permeability zones. Introduction The knowledge of vertical flow properties across a low-permeability stratum is becoming increasingly important in reservoir development, especially when enhanced recovery projects are proposed for stratified reservoirs. Vertical well testing is a technique commonly used to determine values for the in-situ vertical permeability of a formation. Either the vertical interference or vertical pulse test may be used, depending on the amount of time required to obtain the necessary pressure response. The method of vertical interterence testing first was introduced by Burns,1 and later developed by Prats.2 Burns' model is based on the assumption of a homogeneous, infinite-acting reservoir with an average vertical permeability smaller than horizontal permeability. Four geometric parameters are used to computer-generate a type curve for analyzing the test data. One difficulty is that each type curve generated is specific to the four geometric parameters and, hence, to the well completion used. The analysis method proposed by Prats uses a plotting technique that does not require computer solutions. However, his technique is restricted by a point-source assumption; that is, the perforated production and observation intervals must be short compared with the distance between them. The most widely used vertical pulse test analysis technique was developed by Falade and Brigham.3–5 Briefly, the method uses sets of correlation curves relating a dimensionless pulse length and dimensionless pulse amplitude. Corrections can be made to account for the upper and lower formation boundaries. It should be noted that the times as given in the Falade and Brigham technique4,5 are too low by a factor of four.6 A second vertical pulse test analysis method, published by Hirasaki,7 is less general in that it considers only the situation with perforations at the upper and lower boundaries. Both methods use a point-source assumption. All previous vertical interference1,2 and vertical pulse3,4,7 test interpretation techniques were developed to determine vertical permeability in a homogeneous single-layer reservoir. These methods may be applied to stratified reservoirs where permeability contrasts are known to occur; however, they may yield misleading results in these cases where the homogeneous reservoir assumption is not justified. This paper presents an analytical model and interpretation technique to analyze vertical interference test data for tight-zone vertical permeability in a reservoir consisting of two permeable zones separated by a tight zone or a zone of low permeability. Pressure response data in the observation zone are plotted in a ?p vs. ?t format on log-log coordinates and matched against one of two type curves. The result of this match is a value for horizontal permeability in the upper and lower layers and a value for the effective vertical permeability across the tight zone. The type curves included are applicable for a wide range of thickness ratios between the permeable and low-permeability layers. Additionally, use of the model is not restricted by a point-source assumption.

scholarly journals Interactive computer processing and interpretation of pumping test data. A Micro-computer program using dynamic graphics

1985 ◽  
Vol 4 ◽  
pp. 1-98
Author(s):  
Bjarne Madsen
Keyword(s):  
Computer Program ◽  
Groundwater Flow ◽  
Test Data ◽  
Pumping Test ◽  
Flow Equation ◽  
Hard Copy ◽  
Type Curve ◽  
Type Curves ◽  
Wide Range ◽  
Graphic Screen

This paper presents a computer program for analysing pumping test data. The program is interactive and may be used with a minimum knowledge of computers. It can be applied to a wide range of transient problem types, from one dimensional groundwater flow to flow in anisotropic aquifers, horizontally as well as vertically. Various forms of type curves based on analytical solutions to the groundwater flow equation are available for the interpretation. The paper includes a listing of the entire computer program containing a total of about 1. 800 lines. The programming language is a BASIC-version suited for the Tektronix 4054, a graphic screen with a refresh option. This option allows the user to perform type curve matching directly on the screen by moving the chosen type curve to the position where it gives the best fit, in a manner similar to traditional manual chart interpretation. Plots of the measured data may be conveniently reproduced in semilog and log-log diagrams, either on the screen or as a hard copy printed by a plotter. The present version of the program makes use of tape cartridges, both for storing program and data files.

Comprehensive Analysis Of Drillstem Test Data With The Aid Of Type Curves

1976 ◽  
Author(s):  
B.K. Sinha ◽  
J.E. Sigmon ◽  
J.M. Montgomery
Keyword(s):  
Test Data ◽  
Comprehensive Analysis ◽  
Type Curves

Mahakam Field Characterization Using Production Type-Curve With Business Intelligence Application

2020 ◽  
Author(s):  
P. Noverri
Keyword(s):  
Business Intelligence ◽  
Data Gathering ◽  
Production Data ◽  
Type Curve ◽  
Type Curves ◽  
Production Type ◽  
Efficient Data ◽  
Production Behavior ◽  
Factor Type ◽  
Mahakam Delta

Delta Mahakam is a giant hydrocarbon block which is comprised two oil fields and five gas fields. The giant block has been considered mature after production for more than 40 years. More than 2,000 wells have been drilled to optimize hydrocarbon recovery. From those wells, a huge amount of production data is available and documented in a well-structured manner. Gaining insight from this data is highly beneficial to understand fields behavior and their characteristics. The fields production characterization is analyzed with Production Type-Curve method. In this case, type curves were generated from production data ratio such as CGR, WGR and GOR to field recovery factor. Type curve is considered as a simple approach to find patterns and capture a helicopter view from a huge volume of production data. Utilization of business intelligence enables efficient data gathering from different data sources, data preparation and data visualization through dashboards. Each dashboard provides a different perspective which consists of field view, zone view, sector view and POD view. Dashboards allow users to perform comprehensive analysis in describing production behavior. Production type-curve analysis through dashboards show that fields in the Mahakam Delta can be grouped based on their production behavior and effectively provide global field understanding Discovery of production key information from proposed methods can be used as reference for prospective and existing fields development in the Mahakam Delta. This paper demonstrates an example of production type-curve as a simple yet efficient method in characterizing field production behaviors which is realized by a Business Intelligent application

Guest Editorial: Spacing Ourselves to Death

2021 ◽  
Vol 73 (09) ◽  
pp. 8-10
Author(s):  
Justin Hayes
Keyword(s):  
Oil And Gas ◽  
Cash Flows ◽  
Simple Type ◽  
Financial Model ◽  
Type Curve ◽  
Type Curves ◽  
Technical Staff ◽  
Future Performance ◽  
Well Spacing ◽  
Proper Name

If you talk to a typical subsurface professional working on unconventionals today (e.g., a reservoir engineer, completion engineer, geologist, petrophysicist, etc.) as I have in person and through media such as LinkedIn, you will find that many lament one key thing: Our sophisticated models have been reduced too much. Of course, I am generalizing and those are not the words they use; the lamentations come in many forms. The dissatisfaction with oversimplification is most easily observed as dis-taste for the type curve, the simplified model we use to predict upcoming new drills. (Yes, I know many of you will want to refer to them by their “proper” name: type well curve; I will be sticking with the colloquial version.) A simple meme posted on LinkedIn about type curves garnered one of the most engaged conversations I have seen amongst technical staff. The responses varied from something like “Thank God someone finally said this out loud” to comments such as “I don’t know anything better than type curves.” Most comments were closer to the former than the latter. What is even more remarkable is that our investors feel the same. In personal conversations, many of them refer to our type curves simply as “lies.” This perception, coupled with the historical lack of corporate returns, led investors away from our industry in droves. Many within the industry see it differently and want to blame the exodus on other factors such as oil and gas prices, climate change, competition from renewables, other environmental, social, and governance (ESG) issues, the pandemic, or OPEC’s unwillingness to “hold the bag” any longer. If you ask them, though, investors will tell you a simple answer: The unconventional business destroyed way too much capital and lied too much through the type curves. Why is it that both investors and technical staff are unhappy with our ability to accurately model future performance? Why can’t we deliver returns? The typical unconventional-focused oil and gas company has two models that are critical to the business. First is the subsurface model, with which we are all intimately familiar in its various forms, and the second is the corporate financial model, which is focused on cash flows, income, and assets/liabilities. It is unfortunate that the two models are separate. It means we must simplify one or both so they can communicate with each other. How can you observe this oversimplification while it is happening? It is happening when the finance staff say, “Please just give me a simple type curve and well count; I need to model, optimize, and account for debt/leverage, equity, and cash flows.” Meanwhile, the technical staff say, “Please just give me a CAPEX budget or a well count; I need to model, optimize, and account for well spacing, completion design, land constraints, and operational constraints.” Looking back, we know that the winner in this tug-of-war of competing needs was the type curve.

scholarly journals Investigation on Interference Test for Wells Connected by a Large Fracture

2019 ◽  
Vol 9 (1) ◽  
pp. 206
Author(s):  
Guofeng Han ◽  
Yuewu Liu ◽  
Wenchao Liu ◽  
Dapeng Gao
Keyword(s):  
Double Porosity ◽  
Flow In Porous Media ◽  
Connection Form ◽  
Analysis Model ◽  
Pressure Derivative ◽  
Type Curve ◽  
Type Curves ◽  
Multi Stage ◽  
Interference Test ◽  
Straight Lines

Pressure communication between adjacent wells is frequently encountered in multi-stage hydraulic fractured shale gas reservoirs. An interference test is one of the most popular methods for testing the connectivity of a reservoir. Currently, there is no practical analysis model of an interference test for wells connected by large fractures. A one-dimensional equation of flow in porous media is established, and an analytical solution under the constant production rate is obtained using a similarity transformation. Based on this solution, the extremum equation of the interference test for wells connected by a large fracture is derived. The type-curve of pressure and the pressure derivative of an interference test of wells connected by a large fracture are plotted, and verified against interference test data. The extremum equation of wells connected by a large fracture differs from that for homogeneous reservoirs by a factor 2. Considering the difference of the flowing distance, it can be concluded that the pressure conductivity coefficient computed by the extremum equation of homogeneous reservoirs is accurate in the order of magnitude. On the double logarithmic type-curve, as time increases, the curves of pressure and the pressure derivative tend to be parallel straight lines with a slope of 0.5. When the crossflow of the reservoir matrix to the large fracture cannot be ignored, the slope of the parallel straight lines is 0.25. They are different from the type-curves of homogeneous and double porosity reservoirs. Therefore, the pressure derivative curve is proposed to diagnose the connection form of wells.

Test Response of a Turbocharger Supported on Floating Ring Bearings: Part I — Assessment of Subsynchronous Motions

2003 ◽  
Author(s):  
Chris Holt ◽  
Luis San Andre´s ◽  
Sunil Sahay ◽  
Peter Tang ◽  
Gerry La Rue ◽  
...  
Keyword(s):  
Ambient Temperature ◽  
Test Data ◽  
Natural Frequencies ◽  
Comprehensive Analysis ◽  
Experimental Results ◽  
Inlet Pressure ◽  
Rotor Speed ◽  
Test Response ◽  
Feed Pressure ◽  
Feed Temperature

Measurements of casing acceleration on an automotive turbocharger running to a top speed of 115 krpm and driven by ambient temperature pressurized air are reported. Waterfall acceleration spectra versus rotor speed show the effects of increasing lubricant inlet pressure and temperature on the turbocharger rotordynamic response. A comprehensive analysis of the test data forwards regimes of speed operation with two subsynchronous whirl motions (rotordynamic instabilities). Increasing the lubricant feed pressure delays the onset speed of instability for the most severe subsynchronous motion. However, increasing the lubricant feed pressure also produces larger synchronous displacements. The effect of lubricant feed temperature is minimal on the onset and end speeds of rotordynamic instability. Nevertheless, operation with a cold lubricant exhibits lower amplitudes of motion, synchronous and subsynchronous. The experimental results show the subsynchronous frequencies of motion do not lock (whip) at system natural frequencies but continuously track the rotor speed. No instabilities (subsynchronous whirl) remain for operating speeds above 90 krpm. Bearings greatly influence turbocharger (TC) rotordynamic performance.

Unified Decline Type-Curve Analysis for Natural Gas Wells in Boundary-Dominated Flow

SPE Journal ◽  
2012 ◽  
Vol 18 (01) ◽  
pp. 97-113 ◽  
Author(s):  
Ayala H Luis F. ◽  
Peng Ye
Keyword(s):  
Natural Gas ◽  
Constant Pressure ◽  
Curve Analysis ◽  
Production Data ◽  
Gas Wells ◽  
Production Potential ◽  
Type Curve ◽  
Type Curves ◽  
Decline Curve Analysis ◽  
Decline Curve

Summary Rate-time decline-curve analysis is the technique most extensively used by engineers in the evaluation of well performance, production forecasting, and prediction of original fluids in place. Results from this analysis have key implications for economic decisions surrounding asset acquisition and investment planning in hydrocarbon production. State-of-the-art natural gas decline-curve analysis heavily relies on the use of liquid (oil) type curves combined with the concepts of pseudopressure and pseudotime and/or empirical curve fitting of rate-time production data using the Arps hyperbolic decline model. In this study, we present the analytical decline equation that models production from gas wells producing at constant pressure under boundary-dominated flow (BDF) which neither employs empirical concepts from Arps decline models nor necessitates explicit calculations of pseudofunctions. New-generation analytical decline equations for BDF are presented for gas wells producing at (1) full production potential under true wide-open decline and (2) partial production potential under less than wide-open decline. The proposed analytical model enables the generation of type-curves for the analysis of natural gas reservoirs producing at constant pressure and under BDF for both full and partial production potential. A universal, single-line gas type curve is shown to be straightforwardly derived for any gas well producing at its full potential under radial BDF. The resulting type curves can be used to forecast boundary-dominated performance and predict original gas in place without (1) iterative procedures, (2) prior knowledge of reservoir storage properties or geological data, and (3) pseudopressure or pseudotime transformations of production data obtained in the field.

scholarly journals A Sound Assessment of Test Suite Minimization Techniques

2018 ◽  
Vol 7 (2) ◽  
pp. 87-91
Author(s):  
Fayaz Ahmad Khan
Keyword(s):  
Software Development ◽  
Test Data ◽  
Comprehensive Analysis ◽  
Test Suite ◽  
Test Cases ◽  
Test Data Generation ◽  
Data Generation ◽  
Before And After ◽  
New Ideas ◽  
Automatic Test Data Generation

During software development, testing and re-testing occurs frequently to ensure that the software is working correctly before and after modifications. To carry out an effective testing process a test suite is created and executed to detect the faults in the existing code as well as in the modified code. The manual approach of test suite creation and execution is time consuming and labour intensive task as compared to automatically generated test data or test suite. The automatic test data generation is supposed to be an effective way, but a lot of redundant test cases are generated that increase the time, effort and cost of testing. Therefore, test suite minimization techniques are used to further minimize or reduce the number of test cases by selecting a subset from an initially random and large test suite to test the code before as well as after modification. In this study, a comprehensive analysis of the different test suite minimization techniques is presented in order to extend the existing studies and to propose new ideas in this direction.

Sign in / Sign up

Export Citation Format

Share Document