Introduction of Game-changing Drilling Technology
Authors: Schoenmakers J.M. 
Published: December 2007

SPE/IADC Member

This paper describes the structured process of drilling technology introduction in Petroleum Development Oman from planning, through trials to implementation. Examples are given related to horizontal drilling, multilateral wells, coiled tubing drilling, underbalanced drilling and percussion drilling.

The annual technology planning cycle starts with a multi-disciplinary workshop and culminates in the corporate technology plan, with each project described on a project sheet. A vision for future drilling operations has been defined. This provides continuity for technology projects and aids long term planning. It is described in the Appendix.

Drilling trials are prepared and executed in a step-wise fashion. The aim is to minimise the risk and always deliver a producing well. Yard trials and a sequence of field trials are used for this. As confidence in the trialled technology grows and scope for applications is confirmed, services are tendered and the technology is implemented on a wider scale.

Introduction

Petroleum Development Oman (PDO) produces the majority of the countrie's oil from more than 80 oil fields, which present a large diversity in geological settings. The company currently employs 22 onshore drilling rigs. The large number of wells, challenging production targets, an asset based organisational structure and dedicated resources in the form of a drilling technology group, provide a conducive environment for the introduction of new drilling technology. PDO takes pride in a string of technological successes. The most evident is horizontal drilling, which has saved, based on the cost/producibility ratio, in the order of 1 billion dollars over the past 5 years in comparison with vertical wells. Slimming down wells has saved approximately fifty million dollars. Other technologies are starting to provide benefits, e.g. Logging-While-Drilling and Multi-Lateral wells, whilst others are net negative to date (Underbalanced Operations, Coiled Tubing Drilling).

These successes are achieved through an innovative atmosphere amongst PDO staff, made possible by the high volume of work, i.e. 200 well per year, and challenging targets to increase oil and gas production under tight budgets.

A structured approach is required for the guidance and early introduction of game changing drilling technology, which typically has a multi-year development cycle. This was clearly demonstrated when horizontal drilling technology was introduced.

Example 1: Horizontal drilling

The invention of the steerable downhole motor in the early eighties, was the technological breakthrough that facilitated the widespread use of horizontal drilling. Advancements in drillstring design, MWD, bits, and better understanding of hole cleaning and hole stability have supported the worldwide spread over a decade. The pay-out of this technology is in a higher production rate, increased recovery, and better knowledge of the reservoir.

After an early unsuccessful 3-well trial in 1986, the actual introduction of horizontal drilling in Oman's oil fields began in 1990. The 3-well trial used articulated collars, which are still used for short radius build rates. To date PDO have drilled more than 700 horizontal wells, at a pace of more than 140 new horizontal development wells every year (Fig 1). Virtually all development wells are now horizontal. Most wells are of medium radius design (9–13 deg/30m) with the length of the horizontal section between 200 m to 2400 m, averaging 700 metres.

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