Industry experience has shown that frac pack completions can provide effective production stimulation and reliable sand control for unconsolidated sand reservoirs. One of the more rewarding areas of opportunity is in the completion of longer and more complex intervals that can be stimulated with a single frac pack treatment. Here, the cost saving of a single completion versus the cost of two or the recovery of reserves from pay zone sand added to the completion interval can add significantly to the cash value of the well. This paper discusses an innovative screen that has a concentric shroud that can treat two separate and distinct sand lobes during a single frac-pack operation. Two cases histories illustrate the use of an innovative assembly that uses the new screen to enhance the stimulation and sand control results of frac pack completions on unconsolidated sand reservoirs with complex lithology and permeability contrast. The capabilities of this technology have brought a long-sought-after solution to fruition. Introduction Although conventional screens have been very successful in controlling sand production in most situations,1,2 not every well configuration lends itself to traditional screens. For example, in completions where there is a risk of screening-out in the upper part of the completion before the lower part of the completion, a screen-out with conventional screens can prevent the gravel slurry from reaching the lower part of the completion. Questionable applications include:frac packs where potential annular restriction or bridging may compromise sand control or uniform stimulation of the pay intervalfrac packs in intervals where there are distinct layers with different lithologyfrac packs in intervals where there are significant variations in permeability and porosityfrac packs in long intervals where there is concern that a complete annular pack would be achievedfrac packs in highly deviated intervals where multiple fracture initiation may jeopardize complete annular packing. Because of the more complex completions now attempted, the incidence of failures experienced in scenarios such as those listed above have increased. To provide a solution, a new type of sand-control screen assembly that consists of an outer perforated shroud placed over a metal-mesh sand screen has recently been developed. With this assembly, the annular space between the outer shroud and screen forms a secondary slurry flow path to enable bypassing a blockage in the outer annulus between the shroud and the casing. The perforations in the shroud are designed to balance slurry flow control during the treatment and low inflow restriction during production.

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThe use of floating vessels in deep offshore operations and the associated rig heave has made the downhole positioning of tools for frac-packing applications more difficult. To address these problems, sand control tool systems that allow weight to be applied to the packer have been developed. This capability enables the tool position to remain stationary during pumping operations and provides a stable point of reference for other tool positions.While traditional tool designs have been capable of providing a single weight-down position, expansion into deepwater environments has increased the severity of the problem such that one position was inadequate for deepwater environments. A system was needed to provide multiple run-in and circulating positions. Subsequently, tool systems evolved to two-position designs. Again, the ever-expanding development into ultra deep-water environments required further changes. The systems now needed multiple weightdown positions and the capability to allow the tools to be moved both up and down in the wellbore. Finally, tools were needed that could also indicate restrictions in the wellbore and in the actual sealbore diameters.Tool systems have now been developed to meet these criteria. This paper will discuss these innovations and provide information on:The state-of-the-art tool-system options now available to meet the varied frac-packing needs of the industry.A description of the applications where these options can be applied in well completion scenarios.How to determine the most reliable basic system to accomplish the completion objectives.A set of tools ready for testing that can be used to accommodate multiple-zone applications with the only limitation being that that the weight down tool must indicate in a bore that is the same as the seal bore of the packer.How the new tools increase safety and reduce operational costs.

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractAn operator company and service company have used concentric alternative flowpath technology to successfully gravel pack five horizontal openhole completions where reactive shales have caused problems in the past. These horizontal openhole gravel packs were the first for the Nigeria operator company, and were the service company's first use of this concentric alternative flowpath system in a horizontal openhole completion. This paper discusses operational procedures, best practices, and lessons learned during the completion of these wells. Early attempts to manage sand production with predrilled liners had failed, and subsequent attempts to control sand with stand alone screens had also failed. Using a gravel pack was another alternative sand control method, but the presence of reactive shales, a known problem in the field, had to be addressed. Concentric alternative flowpath technology has effectively controlled reactive shales and gravel packed five wells in this field. In these cases, an engineered predrilled outer shroud was installed for hole cleanup and displacement before running the screen and gravel packing. The key factors in successfully completing these wells that will be discussed in detail include:• Improved drill-in fluid designs and effective casing cleanup and displacement methods • Openhole and casing cleaning and preparation prior to running the outer shroud and screen • Outer shroud and screen installation process • Gravel packing method and procedure

Difficulties due to well and water depths, deviations, and rig heave while spacing out production tubing and landing the tubing hanger on subsea completions can significantly challenge space-out operations. Another challenge occurs when attempting to enter the casing at the subsea tree in deep water. During actual completions, subsea currents can produce a bending motion on the riser, causing the bottom of the completion to enter the casing at an angle. If the angle is too great, set-down weight or compression must be added to push the completion through, making shearable-activated travel joints risky. Premature stroking of a standard travel joint from friction in deviated wells is also possible. These problems and the fact that deepwater rig rates are significant, make it imperative that the production tubing string be landed efficiently. Therefore, a successful completion design must manage friction while having sufficient rigidity to land seals into production packers at high angles with limited slack-off weight. This paper discusses a recent deepwater project in Malaysia where these potential problems and others due to the high deviations were possible during the completions. To address these issues, a service/engineering company had developed a long space-out travel joint (LSOTJ) designed to telescope downward in response to a timed application of a compressive load instead of a shearing event as in standard designs. The LSOTJ then slowly scopes downward during lowering of the production tubing until the hanger is landed. The Malaysian operator decided to use the LSOTJ in their development because of its success in the Gulf of Mexico. Eleven of the non-continuous sealing (NCS-LSOTJ) version and three of the continuous sealing version (CS-LSOTJ) were used. This was the first usage of the NCS-LSOTJ in Malaysia, and the first usage world-wide of the CS-LSOTJ. The case history will discuss the completion success. Introduction This field in Malaysia would be the first deepwater development for this operator as well as the first wholly deepwater subsea development in Malaysia. The offshore Malaysia field lies in water depths up to 1,220 meters. The field was to be developed initially using 14 subsea wells with oil exported via a pipeline to a new oil and gas terminal that would be built in Kimanis, Sabah. The production system was to have a capacity of 135,000 B/D. When on production, this would represent 25% of Malaysian oil production. Sweep efficiency was a critical factor in the development of the field, and for that reason, intelligent well configurations were chosen for some of the injector wells. Any natural gas produced along with the oil was to be re-injected into the reservoir to help improve oil recovery. Treated seawater would also be injected into the reservoir to help with pressure maintenance. The 14 subsea wells from 4 drilling centers (A, B, C and E) would consist of 2 single-zone conventional water injector wells, 1 single-zone conventional gas injector well, 1 dual-zone gas intelligent injector well, 2 dual-zone water injector wells and 8 single-zone producer wells.

Spacing out production tubing and landing the tubing hanger in subsea completions is particularly challenging in wells with extreme well depths or in highly deviated well bores, as rig heave can significantly challenge space-out operations. Another problem also can occur when attempting to enter the casing at the subsea blowout preventer (BOP) in deep water, since the subsea currents can initiate a bending motion to the riser, causing the bottom of the completion to enter the subsea blowout preventer (BOP) at an angle. If the angle is too high, set-down weight or compression must be applied to push the completion through, placing shearable travel joints at risk of prematurely shearing. Even after pushing the travel joint through the subsea BOP, the completion design must manage friction induced by well deviations or 'S' curve well bores. Also, the travel joint must remain rigid enough to land seals into production packers at the formation. Often, these challenging scenarios with high angles can be further complicated by limited available slack-off weight. This paper will discuss how the development of new travel-joint designs were capable of resolving challenges such as those mentioned above that were encountered on the the first deepwater subsea development for an operator in Malaysia. This was also the first entirely deepwater subsea development in Malaysia, and at the time of the commencement of its development, an average production of 135,000 barrels per day of hydrocarbon was expected from the project.To address the completion obstacles discussed above, a service/engineering company developed a long, space-out travel joint (LSOTJ) designed to telescope downward in response to a timed application of a compressive load rather than a shearing event as in standard designs. The LSOTJ slowly scopes downward during lowering of the production tubing until the hanger is landed. Equipment development was comprised of two versions of the long space-out travel joint; one version is a non-continuous sealing (NCS-LSOTJ) version, and the other is a continuous sealing (CS-LSOTJ) version This paper will discuss the design and development of the two LSOTJ versions, and the first usage of the continuous sealing version in Malaysia, which was also its first usage world-wide.