Emerging Techniques in Gravel Packing Open-Hole Horizontal Completions in High-Performance Wells

Abstract

Gravel-packing of open-hole highly-deviated or horizontal wells is increasingly becoming a common practice, especially in deep water and sub-sea completion environments where production rates may reach up to 50,000 BOPD or 250 MMSCFD. In these wells, reliability of the sand face completion, in addition to other factors, is of utmost importance due to the prohibitively high cost of intervention or side-tracking and the very high hydrocarbon recoveries required per well. To date the norm in gravel-packing such wells is water-packing or shunt-packing with water-based fluids. With both techniques, filter-cake removal treatments are conventionally done through coiled tubing after gravel packing, pulling out of the hole with the service tool and running in with the production/injection tubing. Furthermore, because conventional gravel-pack carrier fluids are water-based (brine or viscous fluids), water-based drilling fluids are traditionally used to drill the reservoir section to ensure compatibility and improve wellbore cleanup, even if the upper hole is drilled with a synthetic/oil-based drilling fluid. In this paper, we discuss several novel techniques that can substantially improve return on investment in gravel packing of open-hole horizontal completions, through reduced cost and process time, improved fluid management practices, increased productivity and/or reduced risk of future interventions, so mitigating against the risk of sand face completion failure or under-performance. The proposed techniques include:Simultaneous gravel-packing and filter-cake removal with water-based carrier fluids when the reservoir is drilled with a water-based drilling fluid: laboratory data relevant to gravel-packing are given and field case histories are discussed in detail.Simultaneous gravel-packing and cake cleanup with either water or a synthetic/oil-based carrier fluid when the reservoir is drilled with a synthetic/oil-based drilling fluid: laboratory data on cake removal while gravel packing are presented for both water-based and oil-based carrier fluids along with data on kinetics of cake removal.a new service tool that utilizes wash-pipe as continuous tubing and thus allows spotting of breaker treatments immediately after gravel packing: detailed description of the tool and its operation is given.Gravel-packing of highly-deviated or horizontal wells above fracturing pressure. Benefits offered by each of the proposed techniques are discussed in detail along with their current limitations. Introduction A great majority of the highly-deviated and horizontal wells are being completed as open holes, primarily because of their much higher damage tolerance, higher well productivities at high mobilities (kh/µ) and lower cost compared to cased holes. Although most of these wells in areas requiring sand control have been completed with standalone screens, a rapidly increasing fraction of them are now being gravel packed, particularly in deep water, high production rate and/or sub-sea completion environments (currently ca. 40%, and projected to be ca. 60% by 2003/2004). The major drivers for this current trend are the prohibitively high cost of intervention and much higher reliability associated with gravel packs.1,2

Frac-Packing Openhole Completions: An Industry Milestone

“…Unlike conventional frac-packing, this technique does not involve the use of pads. As discussed in an earlier publication 13 , the evidence from the cuttings reinjection processes suggests that gravel packing above fracturing pressure can create propped fractures without using pads. The proposed technique for open-hole gravel packing above fracturing pressure involves the use of a high-leakoff carrier fluid (e.g., a viscoelastic surfactant solution, VES) in conjunction with the shunt technique and a mechanism for isolation of the base-pipe/wash-pipe annulus at selected intervals 13 .…”

Use of Oil-Based Reservoir Drilling Fluids in Open-Hole Horizontal Gravel-Packed Completions: Damage Mechanisms and How to Avoid Them

“…Such a system has recently been discussed in the literature. [7][8][9]17 The results presented in these papers indicate that cake dissolution can be achieved with such a process if an invertable RDF is used, providing increased retained permeabilities and decreased flow initiation pressures. Furthermore, the time scales for inducing high losses can be controlled such that losses (due to rapid cake dissolution) will not occur during gravel packing, but cake dissolution will be completed within the time scales of a roundtrip (involving pulling out of the hole with the work string and running in to the hole with production tubing).…”

“…Although the latter approach is feasible with shuntpacking because this method does not rely on either the cake or the formation properties, as demonstrated through both large scale yard testing under extreme leakoff conditions and field applications, 2, 14-15 a better approach would be to gravel pack and cleanup the cake simultaneously. Such an approach has recently been proposed, 7,9,17 as an extension of the simultaneous gravel packing and cake cleanup approach proposed 16,18 and practiced successfully in 7 horizontal open hole completions for water-based RDFs (three of which have been documented 10,19 ) to S/OB-RDFs. We will describe this approach and give data on flow back characteristics of a S/OB-RDF filtercake through gravel packs.…”

Design Methodology for Selection of Horizontal Open-Hole Sand Control Completions Supported by Field Case Histories

“…full gauge stabiliser and maintaining overbalance) and gravel packing techniques (shunt packing/simultaneous cleanup or water packing/antiswabbing tools as example combinations) have eliminated the recurrence of the problems described in this case history. 32,34 As a general remark, similar horizontal wells in water-drive reservoirs have produced formation sand when gravel placement through water packing has been incomplete.…”

“…This raises the question as to whether OH Frac Packing may be a solution for the future). 34 The criteria point to the use of wire wrap screens, given a net to gross of 80%, regardless of standalone or gravel-pack completion.…”