Evaluation of Well Perforators

API RECOMMENDED PRACTICE 19B THIRD EDITION, JULY 2021

Special Notes

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Copyright © 2021 American Petroleum Institute

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Foreword

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ThisdocumentwasproducedunderAPIstandardizationproceduresthatensureappropriatenotificationandparticipation in the developmental process and is designated as an API standard. Questions concerning the interpretation of the content of this publication or comments and questions concerning the procedures under which this publication was developed should be directed in writing to the Director of Standards, American Petroleum Institute, 200 Massachusetts Avenue, NW, Suite 1100, Washington, DC 20001. Requests for permission to reproduce or translate all or any part of the material published herein should also be addressed to the director.

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Contents

Page

1. Scope 1

2. Normative References 1

3. Terms, Definitions, and Abbreviations 2

   1. Terms and Definitions 2

   2. Abbreviations 2

4. Evaluation of Perforating Systems 3

   1. Evaluation of Perforating Systems under Surface Conditions, Concrete Targets (Section I Test) 3

   2. Evaluation of Perforators using Stressed Rock Targets (Section II Test) 9

   3. Evaluation of Perforator Systems at Elevated Temperature Conditions, Steel Targets (Section III Test) ... 20

   4. Evaluation of Perforation Flow Performance Under Simulated Downhole Conditions (Section IV Test) 26

   5. Debris Collection Procedure for Perforating Guns (Section V Test) 51

   6. Evaluation of Perforator Systems to Determine Swell (Section VI Test) 58

Annex A (informative) Test Target and Equipment—Section IV Testing 61

Annex B (informative) Permeability Measurement—Section IV Testing 64

Annex C (informative) Data Reduction; Expected Flow Rates—Section IV Testing 67

Annex D (informative) API 19B Perforator Witness and Registered Design Program 69

Bibliography 70

Figures

1. Example Concrete Target 3

2. Diagram 1 in. × 2 in. Test Sample Post Failure; Demonstrating Shear Failure Angle Required for a Valid UCS Test 12

3. Diagram 1 in. × 2 in. Test Sample Post Failure; Failed to Demonstrate a Shear Failure Model for a Valid UCS Test 12

4. Suggested Position of Cutter Scratch vs. Bedding Planes 14

5. Test Set Up Schematic 16

6. Schematic Illustration of Steel Target for Elevated Temperature Test 21

7. Typical Axial-Flow Permeability Equipment 30

8. Typical Diametral Flow Permeability Equipment 31

9. Schematic of Typical Testing Equipment 33

10. Typical Radial-flow Geometry 37

11. Typical Axial-flow Geometry 38

12. Productivity Index Data Reduction Graph 43

13. Example Gas Flow Curve Fit to Determine a1 and a2 47

14. Post-Shot Radial Flow for a Gas Saturated Core 48

15. Section IV Standard Test Data Recording Sheet 51

16. Drift Gage Drawing 59

1. Typical Radial-flow Geometry 62

2. Typical Axial-flow Geometry 63

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   Contents

   Page

3. Schematic of Typical Testing Equipment 63

1. Typical Axial-flow Permeability Equipment 65

2. Typical Diametral-flow Permeability Equipment 66

Tables

1. Permissible Variations of Specimen Mold 5

2. Casing and Tubing for Use in Test Target 6

3. Casing Selection Requirements 58

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Evaluation of Well Perforators

1. Scope

   
   

   This recommended practice describes standard procedures for evaluating the performance of perforating equipment so that representations of this performance may be made to the industry under a standard practice.

   
   

   Section 4 provides methods for evaluating perforator or system performance, or both, in four ways:

   
   

   a) performance under ambient temperature and atmospheric pressure test conditions into standard casing and concrete targets (4.1);

   
   

   b) individual shots into Berea sandstone targets at various defined stressed conditions, with wellbore and pore

   pressures at nominally ambient conditions (4.2);

   
   

   c) how performance can be changed after exposure to elevated temperature conditions (4.3);

   
   

   d) flow performance of a perforation under specific stressed test conditions (4.4).

   
   

   Section 4.5 provides a procedure to quantify the amount of debris that comes out of a perforating gun during detonation, and during conveyance out of the well. Section 4.6 provides a procedure to measure the swell of a perforating gun.

   
   

   The purpose of this recommended practice is to specify the materials and methods used to evaluate objectively the performance of perforating systems or perforators.

   
   

2. Normative References

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document applies (including any addenda/errata).

API Specification 10A, Specification for Cements and Materials for Well Cementing

API Standard 19C, Measurement of and Specifications for Proppants Used in Hydraulic Fracturing and Gravel- packing Operations

ASTM A29, Standard Specification for General Requirements for Steel Bars, Carbon and Alloy, Hot-Wrought

ASTM C109, Standard Test Method for Compressive Strength of Hydraulic Cement Mortars (Using 2-in. or [50- mm] Cube Specimens)

ASTM C150, Standard Specification for Portland Cement

ASTM D3740, Practice for Minimum Requirements for Agencies Engaged in Testing and/or inspection of Soil and Rock as Used in Engineering Design and Construction

ASTM D4543, Practices for Preparing Rock Core as Cylindrical Test Specimens and Verifying Conformance to Dimensional and Shape Tolerance

ASTM D7012-14e1, Standard Test Methods for Compressive Strength and Elastic Moduli of Intact Rock Core Specimens under Varying States of Stress and Temperatures

ASTM E389, Standard Test Method for Particle Size or Screen Analysis at No. 4 (4.75-mm) Sieve and Coarser for Metal-Bearing Ores and Related Materials

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