Drilling automation

Management Strategies Optimize Drilling and Completion Operations

During the optimization process, the Castilla field became the model of management strategies for the rest of the fields in the company portfolio.

By 2010, all applicable drilling solutions had seemingly been applied to the Castilla field in Colombia. But new problems were identified, and a model of management strategies was implemented to reduce drilling and completion timing. During the resulting optimization process, the Castilla field became the model for the rest of the fields in the company portfolio. It is believed that this model might also be applied successfully to other fields.

Introduction

In a May 2010 evaluation, several facets of Castilla field operations were assessed: current processes, operations, and technologies; the state of drilling operations by use of management indicators; nonproductive time (NPT); field characteristics; and roles and responsibilities of personnel. The objectives were to prioritize processes by importance, create a process guide, develop a new manpower plan, improve communication, and apply technology efficiently.

Optimization Evaluation Results

Field Characteristics. The Castilla field is 200 km from Bogotá in the Llanos basin. This field has three formations of heavy oil (T2, K1, and K2) to 7,500, 8,000, and 8,500 ft in true vertical depth (TVD), respectively. Most of the wells are drilled to approximately 9,500 ft in measured depth. The majority of the wells are J-shaped, with inclinations from 30 to 70°. The most common operational problems in the field were to be found at approximately 1,000-ft TVD, at the shale formation found immediately above pay zones.

Optimization Model. The optimization process had three principal stages: implementation, consolidation, and optimization excellence. The development of each well had involved five steps during the drilling process: planning, implementation, control, feedback, and optimization. The drilling engineer had to plan the well; implement, explain, and communicate the plan; control the drilling while continuously monitoring parameters, ensuring compliance with the plan and the application of the lessons learned; catalog the lessons learned; and apply these lessons to new optimization plans.

The working optimization model was designed around several major strategies, all developed on the basis of technical limits related to health, safety, and environment (HSE): continuous monitoring of indicators; establishment of only one line of communication; application of short-, medium-, and long-term well vision; and organization based on engineering.

During the measurement phase, new indicators and methodologies, such as the Boston Consulting Group matrix for NPT classification by severity and frequency, were included. These methodologies were not only part of the initial stage of the process, but over time they also became tools for control and monitoring of trends. The initial evaluation was focused on four main areas: management indicators, time to optimize, human resources, and oilfield characteristics. The Boston matrix was used to identify the severity and frequency of NPT. Several technical and operational tools were used to identify characteristics of the oil field, including maps of Castilla losses of drilling fluid and inflows of northern and southern areas; geological maps to identify formation-top depths, faults, dipping layers, and drainage areas of wells drilled; and existing geomechanical analyses.

Evaluation Results. A centralized type of drilling engineering management was developed in which well engineering was applied from a central unit that served several fields at the same time. Perhaps this strategy might have worked in a stable operation, but with the high operational activity that Ecopetrol was carrying out (and taking into consideration that its goal for production growth for 2010 was 12% over the previous year), it was impossible for this strategy to work. Growth was experienced in all business areas: exploration, production, oil exports, and proven reserves.

The drilling program was a document of almost 100 pages. Too much time was needed to read it, and still it offered little operational detail. As for roles and responsibilities, it was noted that drilling engineers, directly responsible for the drilling operation, were spending most of their work time on receiving calls and only a small portion of their work time on engineering tasks such as planning and monitoring the well, resulting in important decisions being made hastily by staff not seasoned in the Castilla field. Furthermore, service companies were making changes to engineering procedures or proposals without the input of Ecopetrol. Because of this post-event methodology, the field leader was spending much of his time solving NPT problems. In addition, the direct responsibility for HSE issues had been handled by one person not working directly for Ecopetrol. Thus, there was no strict monitoring of HSE issues. Finally, a number of specific drilling problems were identified, ranging from administrative (poor management of permits) to technical (unnecessary wiper trips and cementation) concerns.

Engineering-Based Organizational Strategy

Although the drilling leader hired new staff for the optimization process, the same organizational structure was retained in the rigs. However, the leader used an engineering-based strategy to reorganize the roles and responsibilities of all positions (Fig. 1). The most important change took place in the operations engineer position of each rig. This position was retitled drilling engineer and became a planning position, directly responsible for planning, monitoring, and operations of the well. Some duties of the operations engineer, including the logistics of tools and personnel, were delegated to assistant engineers.

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Fig. 1—Information-flow model for improvement performance.

The Ecopetrol representative in charge of drilling operations in the field kept his normal duties, but was expected to adhere to the plan previously established by drilling engineers. If they wanted to change the plan, they were

required to call the operations center in Bogotá and provide an engineering-based justification of their request.

Each service company must submit its engineering products in advance for review by the drilling engineer. Seven optimization engineers were hired, dedicated to supporting specific tasks such as monitoring NPT, managing maps of wiper trips and fluid loss, updating operations, implementing new technologies, and performing several other activities aimed at optimizing the operation.

Single-Communication-Line Strategy

Many of the observed problems were caused by a lack of specific responsibility. To ensure communication processes, tools were implemented by use of all existing channels. Written communication was key, but it would be supplemented by audiovisual communication and teleconferencing.

The wasteful and unproductive drilling program was replaced by an easy-to-read document with strong engineering content. In fewer than 20 pages, the main well data were summarized. The drilling-well-on-paper scheme ensured the detail of each operation, its parameters, time limits, and lessons learned. This document was not made at the whim of site leaders but instead was an important feat achieved with the participation of all involved in the operation.

A regular video meeting was established in which the Bogotá offices were in conference with the personnel of six drilling rigs. At 4 p.m., every rig delivered a report. A complete communications room was implemented in the Bogotá offices. Cameras were installed in the Bogotá communications room and all rig offices to facilitate these meetings.

Each service company maintains personnel within the same field, but it is not necessary for these staff members to remain in the same drilling rig. New staff could not handle operations unless they met adaptability and recognition guidelines to stay in the field. Thus, the dynamics of drilling, created over several months, could be guaranteed, and the lessons learned during this time were not lost.

This process notably improved the working environment. Personnel confidence increased, and interdependence was strengthened.

Vision Strategy for the Short, Medium, and Long Term

When the Castilla optimization implementation began in 2010, many of the targeted problems had their causes in well planning, including construction of negative and nudge sections, problems of collision between wells, very short or very long vertical sections for the angle of arrival at the target, sudden changes in the angle of arrival at the target, land-purchase issues for the cluster, problems with union strikes in certain sectors of the field, and flooding problems in the field.

A goal was therefore set for a single well in advance (short term), a cluster in advance (medium term), and well campaigns in advance (long term) as fundamental parts of the optimization between 2013 and 2016. By planning far in advance, the planning of the next well begins when starting to drill the current well. This allowed a reasonable time to apply lessons learned and operational practices, and to adjust formation tops, directional profiles, and bottomhole assemblies.

Likewise, when drilling began on the first well of a cluster, the next cluster was planned, which involved purchasing land, setting targets to optimize directional plans, monitoring civil works for locations, acquiring permits from the government (which required a minimum of 30 days from the filing of documents), and engaging in socially conscious interaction with the community, among other tasks.

Results

The total drilling and completion time of the Castilla field for 2010 was reduced by 35%, from an average of 29 days to 19 days. The days/1,000 ft indicator was decreased from 4.2 to 1.9. Completion times were reduced by 40%, from an average of 6.7 days to 3.7 days. The cost savings was greater than USD 50 million for the campaign. The level of commitment, awareness, and knowledge in HSE rose at all levels. The frequency of HSE incidents did not rise despite the man-hours in field operation increasing by 50%.

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 165325, “A Successful Optimization Case of Drilling and Completion Operations Through Management Tools and Strategies,” by Oscar R. Silva, Guden O. Silva, and Luis I. Valderrama, Ecopetrol, prepared for the 2013 SPE Western Regional and AAPG Pacific Section Meeting and Joint Technical Conference, Monterey, California, USA, 19–25 April. The paper has not been peer reviewed.