簡介：2008年11月在馬來西亞舉辦的SPE應用技術研討會討論了小尺寸井防砂技術，64名參會人員討論了先進的防砂技術及最近該項技術取得的進展。

Remedial and slimhole sand control completions took center stage at a recent SPE Advanced Technology Workshop (ATW) held in November 2008 in Penang, Malaysia. Titled “Chasing Lost Reserves with Remedial and Slimhole Sand Control,” the ATW reviewed methods for maximizing recovery of reserves in place by using economical through-tubing and slimhole sand control technologies.

Over the course of three days, 64 participants from 25 different organizations and 11 countries reviewed state-of-the-art sand control technology and recent technical advancements. They also benefited from the experience of other operators who shared case histories and established a network for information exchange with fellow participants.

Cochairpersons Michael Bailey (Drilling and Completions Engineer with ConocoPhillips) and Raymond Tibbles (Stimulation and Sand Control Adviser, Middle East and Africa, for Schlumberger), opened the ATW with an overview of the goals and objectives for the workshop. They encouraged all attendees to participate with any lessons learned from sand control technologies that they had applied.

This was followed by the keynote address by Haji Kamaludin Bungsu, Asset Manager (Western Asset), Brunei Shell Petroleum (BSP) Company. Bungsu’s speech provided an overview of the reserves recovery challenges facing operators in the region, with particular emphasis on the cost and time required to develop new assets and the need to recover the maximum amount of reserves from existing developments. He then discussed the problems associated with brownfield sand production, either due to failure of primary sand control or late-time formation failure when no sand control was installed. He finished with a list of some of the options BSP was exploring to address these issues, while reiterating the need for more and better tools for later term sand remediation and better working relationships between operators and service companies.

Case studies focus of technical sessions
The first technical session was a discussion on the economic drivers for remedial sand control and the need to think about a well’s entire productive life during the initial design phases. An overriding message was how initial completion choices drive the decisions for the rest of the well life and how some simple changes can produce a significant impact. One example detailed how increasing the size of slimhole completions from 3.5 to 4.5 in. can create many more remedial possibilities at lower risk.

The next two sessions reviewed the various techniques available for through-tubing and slimhole sand control. Discussion topics ranged from resin consolidation and screenless fracture packs to through-tubing gravel packs, vent screens, and expanding tubular applications. In addition to discussing the techniques themselves, much time was devoted to weighing the risks associated with these techniques and their impact on productivity.

Case histories were presented from around the world, including representation from most of the Southeast Asian countries (China, Japan, Indonesia, Malaysia, Brunei, Thailand, and Australia) as well as Europe, North America, and South America. These case histories demonstrated the vast difference in job frequency between the US Gulf of Mexico and the rest of the world, with the vast majority of jobs being performed in the Gulf of Mexico. It was quite clear that there is much opportunity to apply these technologies more consistently in Southeast Asia.

Technical sessions on the second day were devoted to lessons learned from successful and unsuccessful sand control completions. The challenges of well intervention in very mature wells were discussed, and the point was stressed that the actual sand control portion of an intervention is not always the cause of success or failure. In many instances other well problems such as corrosion, cement bond, and packer leaks become the key focus of whether the intervention will succeed. In addition, some failures of both primary and remedial sand control can be attributed to poor perforating, acidizing, or other completion practices.

The third day opened with additional case histories on recompleting with a sidetrack and a monobore, screenless fracture packing, and slimhole openhole gravel packing. One case study presented a study in which nearly every type of sand control was attempted with a 70% failure rate. While the target of the discussion was how to remediate the failures, the focus shifted to discussing what could have gone wrong with the process to deliver such poor results. After reviewing these case histories, a strong recommendation for detailed post-project reviews/look backs was made, as this was considered the most effective way to capture project knowledge.

Breakout session asks what’s next, what’s needed
A breakout session followed in which 5 groups comprised of 10 to 12 people brainstormed key topics and provided potential opportunities and solutions. Group 1 was designated “Twilight Year” (sand control solutions for mature fields). This group focused on how much sand production an operator might tolerate, the challenges of brownfields (failed gravel packs, monobore or conventional wells, multilayered zones, depletions, and so on), and types of old technology that have been implemented unsuccessfully. The group identified several solutions for these challenges, including coiled-tubing and through-tubing gravel packs, finding and sealing off the sand production, and fracturing past the problem zone.

Group 2 was designated “Collaboration, Collaboration, Collaboration! What Can the Sand Control Industry do Better to Plan Sand Control Well Interventions and Initial Completions?” It identified several challenges to effective collaboration, including intellectual property, project planning, data access, technology application, and competency levels. Suggested solutions included better licensing facilitation between operators and vendors and ensuring that intellectual property is secured before disclosing information across parties. The group stressed that early involvement between the operator and vendor during concept generation and project planning, coupled with a clear and structured exchange of information, are important.

Group 3 discussed sand prediction models and the need to integrate these models early between operators and service companies, sand management philosophy plans, the importance of understanding reservoir potential, and full lifecycle cost evaluation on early prevention versus remedial (differ investment for more flexibility) sand control. Group 4 suggested ways in which SPE and the sand control community could ensure better communication of slimhole sand control techniques going forward, including more SPE conferences to debate brownfield sand control, dedicated technical sessions in SPE conferences, implementing a sand control Technical Interest Group on SPE’s website, and developing a “Sand Control Cookbook and Menu” that guides engineers through the field basics of a sand control job and includes do’s and don’ts.

The fifth breakout group took a “Crystal Ball” approach to discussing which sand control considerations should receive greater attention in a well’s predevelopment planning. The group assessed that slimhole sand control should be designed such that productivity and reservoir connectivity are preserved. Planners also need to have a good understanding of the long-term utility plans for the wellbore, as well as the expected sand production forecast. They need to have a good logistics plan in place in terms of equipment and manpower supplies for the sand control completion well before the job is to begin.

The technical program ended with discussions on new technologies and tools that had not yet received wide acceptance or use. The reviewed technologies included the use of coiled-tubing drilling in slimhole sanding environments, the use of swelling elastomers, and a new screen design to prevent catastrophic screen failure. This was followed by a discussion of depth filter screens versus surface filter screens. While none of these were considered “silver bullet” technologies, attendees were still encouraged to see that advancements were continuing on many different fronts.