Abstract

Extensive development has been made in the field of wear evaluation of hardfacing materials for downhole applications. These improvements have been industry driven to optimize drilling operations and reduce cost. Previous testing methods such as DEA-42 presented multiple hardware and process deficiencies which recorded results which were inaccurate, unreliable and not repeatable. An evolution of both hardware and processes for hardfacing material testing was developed over a 36-month period through laboratory testing and data evaluation.

This new methodology has been applied to the evaluation of hardfacing materials in both open and cased hole environments. Not only does it provide more reliable data, it also provides the flexibility to test different fluids, casing grades and varying open hole media. Actual material properties such as friction factors and wear rates have been successfully and accurately measured. It has also been used to identify break-in periods for different hardfacing materials.

The methodology has demonstrated repeatable and accurate results for wear characteristics for hardfacing materials under various conditions. Multiple hardfacing materials have been evaluated and their performance compared through this methodology. This methodology greatly surpasses previously established and outdated industry standards. This methodology was employed to engineer and develop a fourth-generation casing friendly hardfacing material currently in service.

This novel approach provides reliable wear characteristics data for available hardfacing materials. It provides a benchmark for industry evaluation of hardfacing materials previously not available in the industry. The use of this technology will aid in the development, selection, and performance evaluation of hardfacing materials for modern and complex well programs. It will improve downhole drilling performance by providing better selection of hardfacing materials.

Introduction

Since the development of hardfacing materials there has been the need to evaluate their performance. The evolution to increasingly complex and costly drilling programs has made this task even more necessary. There is also the need to understand and develop methods for testing hardfacing materials that model specific downhole applications. The industry saw this need and addressed it by forming task groups dedicated to study the topic. One of the initial attempts to quantify hardfacing performance was undertaken by the Drilling Engineering Association (DEA-42 project to Develop Improved Casing Wear Technology). The main task for this group was to develop a testing method to evaluate and quantify casing wear effects. While this methodology presented a good start, it has allowed many opportunities for improvement.

Several hardware iterations were developed to study and initially mimic the methodology originally set by the DEA-42 test procedure. Each new hardware version offered improvements over its predecessor as new features and flexibility were added to the hardfacing testing methodology. The result has been an innovative testing procedure for casing wear that can evaluate cased and open hole conditions with extreme accuracy and repeatability. The hardware set up allows for direct determination of actual coefficient of friction values versus calculated values of friction factors.

This new approach for evaluating casing wear has been employed in the development of a fourth-generation (4th-Gen.) casing-friendly hardfacing material. The ability to use this hardware and methodology in the evaluation of hardfacing materials has resulted in a better understanding and a highly accurate way of determining material properties. This methodology has also been utilized to determine new and improved materials to be used in drilling operations where the material may be exposed to casing wear.

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