RIASSUNTO
Abstract
This paper discusses the first well in which an expandable screen and expandable liner hanger were installed in a horizontal openhole well for Saudi Aramco. Wells in this area require sand control; however, alternative sand control solutions presented some potential problems in the Saudi Aramco wells. Supporting the borehole by packing the annulus space with gravel to prevent pockets in the screen/openhole annulus is a viable solution in some sand control environments; however, Saudi Aramco decided to investigate an expandable sand screen that has an expandable steel base pipe designed to protect the wellbore from collapse and maintain screen integrity. This screen design is considered to be the strongest in the market, with 2,500 psi collapse strength. The screen is run inside the open hole, and after expansion, the screen extends to an outer diameter that is equal to the openhole inner diameter.
The case history data will include the completion design process and a description of the successful deployment of 1,310 feet of the expandable screen into the horizontal lateral. Before expanding, the screen O.D. was 5-3/8 -in, and after expansion, it had enlarged to the open hole ID of 6-1/8-in. This expandable deployment is significant as it was not only the first application of expandable, rigid, perforated base-pipe screen in the Middle East, but it was also the longest deployed to date for this type of 6-1/8 -in. expandable screen worldwide. This application was also the first completion in which an expandable liner hanger was used in the same well as an expandable screen in the Middle East.
The well has been put on production and has shown excellent productivity as well as sand control.
Introduction
Located 180 km south of Riyadh, the capital of Saudi Arabia, the Hawtah Field was discovered in 1989. (Fig. 1) Hawtah is one of several small fields located along the Hawtah Trend (others are Ghinah, Hazmiyah, Nisalah and Umm Jurf). The Trend runs approximately 30 km east to west and 50 km north to south. Production in Hawtah comes from the Unayzah sandstone and consists of Arabian super light (~50° API) sweet crude oil. Because this reservoir has little associated gas, electrical submersible pumps (ESPs) are used to generate production of approximately 200,000 barrels of oil per day.
Gravel-pack completion techniques were employed during Hawtah's development phase, because sand production from some weakly consolidated Unayzah sandstones was noted during early testing and production.
In order to exploit a thin producing interval in existing vertical wells that were ‘mothballed' due to low productivity and high water cut, Saudi Aramco initiated a program to re-enter these wells and recomplete them as horizontal producers. This program included provisions to evaluate different sand- control techniques including stand-alone screen systems, pre-packed sand screens, premium sand screens, openhole gravel pack, and various types of expandable sand screens.
Hawtah 50 (HWTH-50), drilled in 1992, was completed with an ESP in late 1993 and re-completed with a gravel pack completion in 1996. In 2005, with the well shut in due to low oil productivity and high water cut, a workover program was initiated with the intention of drilling a horizontal lateral and installing an expandable sand screen completion across the horizontal interval.
This paper details the planning and installation process from program development through completion. Initial production information is also provided.