This paper addresses specific casing equipment concerns and provides a flow of the decision-making process needed in the designing phase before a cementing operation. A plan for success is also included that can be applied to any conventional cementing job. An essential factor in successful zonal isolation operations is the proper selection and use of the cementing casing equipment. This selection and design process requires a cooperative team effort with members from the operating company, the drilling staff, the drilling contractor, and the service companies. Key elements of this process that will be discussed include:
A cementing plan that addresses the specific parameters of the well. A "cookie-cutter" approach requires less planning time, but can ultimately result in higher costs and longer cementing operations because of unexpected problems.
Appropriate cementing floating equipment to help ensure fewer problems when running casing, greater efficiency, proper mud conditioning with less risk of excessive surge on the formation, and greater drillability is maintained.
Appropriate cementing plugs to help maintain fluid separation during cementing, minimized cement sheath inside the casing, reduced need for scraper trips, reduced shoe track contamination, and improved annular cement quality near the shoe.
Appropriate casing centralization helps ensure fewer problems, reduced risk of sticking, adequate standoff, and improved overall displacement efficiency.
This paper was prepared to train inexperienced personnel in the proper selection and use of cementing casing equipment. Such training helps ensure adequate skills in prejob planning and onsite operations.
During the initial phase of planning an oil or gas well, many factors must be considered. Factors include lease details, partner relationships, and job execution details. Related to factors to be addressed during the actual well construction phase of the well, cementing is one key component that affects the life of the well-not only during the production phase, but also during abandonment. For the purpose of this paper, cementing will relate to the placement of a settable cement slurry in the annular space around the casing for the purpose of zonal isolation. Zonal isolation is required to prevent inter-zonal fluid communication behind the casing. Such communication can cause problems over the life of the well that can be costly to repair. In the grand scheme, it is much less expensive to perform a good primary cement job than to conduct future remedial operations. Cementing operations consist of three main components:
the fluids to be pumped (slurry/spacers/flushes),
surface mixing/pumping equipment, and
downhole tools such as cementing casing equipment. The cementing service company generally provides the knowledge and expertise for Items 1 and 2. However, there are many suppliers of cementing casing equipment and a lack of industry standards for cementing casing equipment. Purchasing agents and drilling engineers are often left to their own devices to make decisions as to what and how cementing casing equipment will be used. This paper discusses the selection and application of cementing casing equipment in three main categories:
floating equipment,
cementing plugs, and
casing attachments.
