in the traditional hole drilling method the in-plane stresses are studied in detail and the interlaminar stresses are not taken seriously. the interlaminar stresses on the free edge of composite materials are important and can cause matrix cracking and delamination. inserting holes in composite laminates causes free edges and it can induce interlaminar shear and normal stresses. in this researc...

Determination of optimum location for drilling a new well not only requires engineering judgments but also consumes excessive computational time. Additionally, availability of many physical constraints such as the well length, trajectory, and completion type and the numerous affecting parameters including, well type, well numbers, well-control variables prompt that the optimization approaches b...

SUMMARY The use of composite laminates in complex structures has increased significantly. However, there are still some issues when considering their use, mainly related with machining, leading to some difficulties and lack of acceptance. In this work, a methodology to evaluate drill geometry and feed rate based on thrust force and delamination extension is presented. INTRODUCTION For the past ...

Logging while drilling (LWD) is a drilling technique which obtains and transmits the logging data during oil/gas drilling operations. Because of the limited available transmission bandwidth of mud channel, how to improve the bandwidth utilization becomes a critical problem in LWD research. In this paper, by discussing the information entropy of real logging data, we find that the original encod...

The data measured by well bottom sensors can be transmitted to the surface through the drilling mud during oil drilling operations. This article introduces a data processing scheme for a wireless data transmission application via mud. The detailed signal processing procedure is given, and several data processing techniques used are discussed, mainly including data encoding and signal integratin...

Feasibility of drilling with supercritical carbon dioxide to serve the needs of deep underbalanced drilling operations has been analyzed. A case study involving underbalanced drilling to access a depleted gas reservoir is used to illustrate the need for such a research. For this well, nitrogen was initially considered as the drilling fluid. Dry nitrogen, due to its low density, was unable to ge...

During the assembly of parts, drilling is usually final procedure in these implementations. Any fault that contributes to dismissal components constitutes a costly loss. In various research fields, including automotive, aeronautical, etc., PMC materials are finding increased implementations, and, consequently, need for precision machining composites has significantly grown. To its characteristi...