New Technologies Enhance Operational Efficiency in Difficult Gravel-Pack Operations
Authors: Lima Everaldo , Pounds Rob , Borin Gustavo Ribeiro , Pereira Alexandre Zacarias Ignacio 
Published: October 2008

Although extended reach and horizontal wells in deepwater fields have presented many difficult challenges, operators have been willing to accept the challenges because of the substantial net reserves that the deepwater fields offer. Unfortunately, although promising new technologies that target the more extreme conditions inherent to deepwater completions have been introduced, many operators have hesitated to try them because they lack proven track records. Fortunately, this has not been the case with one operator, and this paper will discuss the innovative technologies that were employed to successfully perform two "firsts" in gravel pack completions in complicated wellbore scenarios in a deepwater subsea field.

The first job is the longest deepwater horizontal gravel pack (HZGP), run in Brazil. 75,000 pounds of gravel was placed in a 2,730-ft openhole section in 2,621 ft of water from the Ocean Alliance rig. The technologies that were instrumental in the success of this completion included special packer technology, a multi-position weight down tool with a HZGP pressure maintenance assembly, and a new type of sand control screen. Despite the long slant section (6560 ft @ 60 degrees) and openhole length, installation of the sand control completion was smooth, never reaching more than 10,000 pounds of drag.

The second job used a realtime operations (RTO) data acquisition and visualization system during a gravel pack procedure. The system employs advances in traditional data management and networking to allow the personnel at the wellsite as well as all remotely stationed personnel to monitor critical well parameters so that immediate decisions on procedural changes can be made. The system allowed the service personnel and operator to monitor the job's execution and adjust pumping parameters as needed. This job illustrates the enhanced capabilities that can be gained from adapting innovative techniques to traditional procedures. The best practices from these completions will be used in all future jobs. This paper illustrates the importance and gains possible from considering new technologies and applying them where feasible.

History of the Fields

The deepwater subsea fields are approximately 100 miles east of Macae in Block BC-50B in Brazil's Campos Basin. Development of the two fields covers an area of 142 square miles that will be serviced by two floating production storing and offloading (FPSO) vessels that will receive production from 55 subsea wells. Water depths of the wells range from approximately 2800 to 3800 ft. Recoverable reserves for the first field are estimated to be at 867 million barrels of oil and 375 billion cubic feet of gas. The estimated reserves for the second field are 362 million barrels of oil and 141 billion cubic feet of gas.1 The location of the fields can be seen in the map in Fig. 1.

The most prolific Brazilian turbidite reservoirs are included in the Upper Oligocene/Lower Miocene section. The oil is concentrated in seven oil fields.