Oil production from North Kuwait carbonate reservoirs are challenging because of factors, such as high permeability streaks, poor microscopic sweep efficiency, and low mobility ratios, all of which can dramatically impair production rates and oil recoveries. Despite tremendous efforts related to waterflood research, oil recovery in carbonates typically remains low. New technology and approaches are required to increase and sustain oil production to access and drain immense amounts of remaining oil-in-place.This paper presents the results of collaborative work procedures applied to a selective number of wells to increase production performance in the Sabriyah Mauddud field pilot under the Kuwait Integrated Digital Field (KwIDF) project umbrella. KwIDF is part of a comprehensive strategy undertaken by an operator to enhance overall oil production by the application of digital oilfield (DOF) concepts, which involves (1) well instrumentation to provide enhanced real-time data availability, (2) upgraded power and communications infrastructure to support field instrumentation and control real-time data, (3), creating collaborative decision centers to enhance asset team processes across physically separate locations, and (4) providing a platform to increase effectiveness through automating work processes and to shorten observation-to-action cycle time.The Sabriyah KwIDF pilot involves 44 producer and five injector wells producing about 7% of total Sabriyah field production. The main objective of this effort was to maximize and sustain oil rates and reduce well decline while honoring safe well operating envelope constraints. As a result of this effort, production gains have been certified in 10 wells of the pilot area to date. This success has been achieved by carefully analyzing past performance and adjusting well settings to realtime production conditions using the operator's digital infrastructure.This paper describes how this optimization methodology provides improvements to short-term production rates while honoring safe well operating envelope and presents case histories illustrating the benefits from the automated workflows and collaborative decision approach. The average sustained oil gain was 395 BOPD, or 37%. The total sustained oil gain reached 3,949 BOPD (34%), with a cumulative production gain of 756 thousand barrels for the evaluation period.

The first multilateral well in Trinidad was recently drilled and completed in the 759 area of the northern Soldado Field, offshore Trinidad in approximately 60 feet of water. A multilateral completion was selected over conventional well construction to horizontally access heavy-oil reserves in the Forest 4B and 4C sands, located at true vertical depths of 3850- and 4000-ft respectively. Since the formation parameters included poorly sorted, non-uniform formation characteristics, the completion would have to employ some method of sand control. This well represents several "firsts" for this area. It is not only the first multilateral well in Trinidad but is also the first in the area that integrated sand control with a multilateral technique. This paper will discuss the planning, special considerations, and implementation of the techniques chosen to interface sand control into a multilateral well. After reviewing many possibilities, horizontal openhole gravel-pack technology was selected to provide sand-exclusion. A TAML 4 multilateral well junction was selected because it offered a cemented junction with full casing-drift access across the mainbore/lateral interface. In addition to the planning, special considerations, and implementation of horizontal gravel pack into multilateral technology, the paper will discuss lessons learned and future considerations. Introduction The S-836 heavy oil development well is located in the 759 area of the northern Soldado field, which is approximately eight (8) miles northwest of Point Fortin, Trinidad (Fig. 1-2). The water depth in the area is 60 feet. The target reservoirs were the Forest 4B and 4C sand bodies, which are part of the Pliocene geological period, and were deposited in tidally influenced, fluvial-deltaic environments that comprise a series of complex channel systems. The depths of the sand bodies range from 2800 to 4000 feet true vertical depth (TVD). The surface oil viscosity of the 4B and 4C sands is 5100 and 360 centipoise (cP), respectively. The hydrocarbon in place in the 759 area is estimated at 22 MMBO with a recovery factor of 16 percent. Prior to constructing the S-836 multilateral well, the traditional well construction method had been a vertical-to-deviated cased-hole completion that used either gravel packing or frac-and-pack sand-control methods. Submersible pumps and gas-lift production systems were typically deployed to provide artificial lift in heavy-oil applications.1 The S-836 well construction strategy had multiple objectives. First, the well path was to provide optimal reservoir exposure into the 4C and 4B sand bodies. Optimal reservoir exposure meant horizontal well paths through each sand body. Effective formation sand exclusion was another objective. Due to the highly unconsolidated nature of the reservoir rock, horizontal gravel-packs would be required to provide effective sand control while maintaining high production rates. In addition, an effective sand-control system would maximize reservoir depletion and minimize maintenance and remedial workover expenditures. The last and most important objective was achieving economic success through maximized production rates. Both sand bodies would be commingled and produced to surface using a progressive cavity pump (PCP). The lower-lateral gravel-pack would consist of approximately 1700-ft of premium screen and would penetrate the 4C sand. A pressure-maintenance, horizontal gravel-pack system would be used to perform the gravel pack sand.

Two common challenges to sustain production in North Kuwait (NK) include (1) management of artificial lift equipment run life and (2) reduction of production decline through pressure maintenance by water injection. Standard electric submersible pump (ESP) management guidelines promote practices to protect ESP run life while sacrificing well production rates. However, using operating rates that are not always safe can permit optimum reservoir recovery. Better management of well production targets is required to maintain safe ESP operation ranges while pushing the limits to increase production. A methodology has been developed to continuously optimize the well production potential without surpassing its safe operating envelope, keeping pump intake pressure (PIP) above the bubble point, ensuring optimum delivery at the surface, and minimizing pump downtime. This workflow was developed to assist the engineers in expediting data analysis and interpretation. This paper describes the developed production optimization methodology, which enables short- and long-term production enhancement while honoring reservoir, ESP, and surface constraints. The process involves historical and real-time data collection and production test interpretation. From this analysis, the best estimations of short- and long-term well production potentials are identified, and the correspondent action plans are determined. The developed workflow and the result of such an iterative production optimization process are illustrated. To date, as a result of this effort, an average of 8% in production gains has been certified in a number of wells in Sabriyah, NK.

Maximizing recovery from strong water drive, permeable reservoirs in North Kuwait usually require a combination of approaches. Implementing partial perforating techniques across the oil column above the oil/water contact and installing tubing sizes that secure maximum natural flow life cycle are presently utilized to extend the natural flow life cycle in strong bottom- and edge-water drive reservoirs. Limiting production rate at or below critical coning rate, and conversion to Artificial Lift when the water cut increase forces cessation of natural flow, further improve the ultimate recovery of oil from these reservoirs. In pilot Well-A, approximately 55% of the oil column above the Oil/Water contact was perforated on initial completion. Within 6 months from initial completion, the Watercut increased from 0% to 53%, then gradually increased to 74% over the next four years of natural flow life. Before the natural flow ceased completely, the well was worked over to install the innovative Downhole Water Sink completion. This completion design comprised of a very short perforated interval at the original depth of the Oil/Water contact and with another perforated interval across a highly permeable aquifer below the layer of interest. A shrouded ESP with Y-tool assembly was then installed, able to generate a drawdown just below the original OWC that is greater than the drawdown across the originally perforated interval. This pressure sink created at the OWC controls the further development of the water cone around the wellbore thereby increasing the maximum coning rate, in addition to accelerating and increasing the ultimate recovery from this water-drive completion. The excessive water that is usually produced to surface, and processed along with the oil, is now significantly reduced since most of it is now re-directed to a deeper non-oil-producing aquifer. Though the watercut is never eliminated at the oil perforations, the natural flow life cycle is extended, and thereby the ultimate recovery considerably improved. Actual % improvement is yet to be determined since the watercut of the produced fluid at surface has not yet risen to the level that causes cessation of natural flow. This pilot application of the Downhole Water Sink technology to this North Kuwait water-drive reservoir opened up immense opportunities for comparable recovery improvements in similar and even larger water-drive reservoirs in other Assets within the company. Where reservoir pressures are insufficient to maintain natural flow, a dual ESP system is already designed to lift the oil column using the same Downhole Water Sink principle.

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThis paper discusses the first multilateral well drilled in Trinidad and the unique integration of techniques that allowed sand control procedures to be implemented as well. The well was recently drilled and completed in the 759 area of the northern Soldado Field, offshore Trinidad in approximately 60 feet of water. A multilateral completion was selected over conventional well construction to horizontally access heavyoil reserves in the Forest 4B and 4C sands, located at true vertical depths of 3850-and 4000-ft respectively. Since the formation parameters included poorly sorted, non-uniform formation characteristics, the completion would have to employ some method of sand control.This well represents several "firsts" for this area as it not only represents the first multilateral well in Trinidad but also is the first in the area that integrates sand control into a multilateral.After reviewing many possibilities, horizontal openhole gravel-pack technology had been selected to provide sandexclusion. A TAML 4 multilateral well junction was selected originally because it offered a cemented junction with full casing-drift access across the mainbore/lateral interface. When sand was encountered above the junction area, a completion workover was required to convert the existing TAML 4 multilateral junction into a TAML 5 to gain pressure integrity across the junction area.The paper will present the initial planning, special considerations, methods for implementation of horizontal gravel pack into multilateral technology, and finally, the rework operation later required for junction conversion.