Kuwait Oil Company introduced new fluid practices to improve producibility in the Minagish oolitic limestone reservoir in Umm Gudair field. The approach was designed to minimise formation damage in the reservoir section and apply a more effective filter cake removal technique during the well completion. Experience on offset wells and results of return permeability studies showed that specially designed water-based drill-in fluids with optimally sized acid-soluble bridging particles were the preferred fluids for open hole completions on the Minagish reservoir. For removal of the cake and low permeability crush zone created by the drilling process a formic acid precursor (FAP) was used. The precursor is added to the completion fluid and reacts slowly with brine to release formic acid in the reservoir section. Conventional acidisation with HCl can cause wormholes, localised leak-off and failure to treat the entire interval effectively; FAP is in a neutral condition when placed. Localised reaction and loss zones are avoided and the released acid can act uniformly on the entire interval. Four wells in this area were sidetracked due to depletion in pressure and increasing water cut. All utilized the same drill-in fluid. Subsequently wells UG 116ST and UG126ST were stimulated with HCl, whereas UG 38STRE and UG 110ST were treated with the FAP. The two wells treated with the FAP had producibilities about twice those treated with HCl. The combination of well designed drill-in fluid and FAP has shown great promise of facilitating the drilling process and increasing the producibility of the well with significant economic benefit. This paper addresses practical applications of the drill-in fluid and the breaker and reports on several additional benefits that were obtained. Introduction The Umm Gudair field, situated in West Kuwait is managed by the Kuwait Oil Company (Gohain et al. 2007). The field is composed of two elongated dome like structures that are separated by a saddle shaped structure. The smaller westerly dome has a structural closure that trends north-south whereas the larger and broader dome in the east extends southwards. The field has been in production since 1962 when oil was discovered in the Minagish Formation. This formation is a massive peloidal-oolitic limestone reservoir with porosity in the range of 10 to 25 porosity units and average permeability about 100 mD but as high as 1000 mD at some intervals. The formation is depleted due to years of production and output is typically enhanced by pumps. Traditionally, the practice has been to drill this formation with a standard KCl/polymer fluid with sized calcium carbonate, since bottonhole temperture was about 180oF such a fluid was considered to be adequate. The reservoir section was left barefoot, stimulation with HCl was applied using a coil tubing unit and production was assisted by an electrical submersible pump connection. Commonly, production wells had horizontal drainholes with diameters of 6.125 or 4.75 inches and length of 1500 to 2000 ft. Generally speaking, drilling the reservoir section involved few issues but stimulation was more troublesome; problems included differential and mechanical sticking when running coiled tubing and subsequent increasing water cut. In 2006 it was decided to drill a new trial well (UG 132) in a hitherto undrained part of the field and to position it accurately within the formation in order to test new approaches to drilling techniques, the formulation of drilling fluid and filtercake clean up procedures. For example (Gohain et al. 2007), the horizontal drain was to be positioned approximately 450 m west of an abandoned well and a minimum of 65 ft above the oil/water contact. The drilling operation involved a "world first" utilisation of an advanced proprietary rotary steerable system together with logging while drilling (LWD) imaging technology. Optimisation of the drill-in fluid was based on typical core samples that had been collected earlier from an offset well and the new approach to the system for cleaning drilling damage avoided the use of hydrochloric or other live acid; instead a system was applied that was neutral when first spotted in the horizontal section but released acid in situ over a period of several hours.

fax 01-972-952-9435. AbstractAfter the liberation of Kuwait, a large number of wells were blown up by the Iraqi troops, and some needed to be worked over before re-producing them. Around 100 wells were intact and were put back on production shortly after the liberation. Those wells are originally 40 to 50 years old, and the wellhead equipment on those wells were not changed or reconfigured with the current API standards until this date. Workover operations were delayed due to several issues concerning the wellheads. A project was assigned by KOC management in 2002 to inspect those wellheads and submit a report with the current status of the equipment, problems, and solutions.As a result of a full research made on those intact wells, the wells were segregated into 4 categories depending on the integrity and operational issues of the wellhead equipment. It was decided that some of those wellheads would only be reconfigured using a combination of the old and new equipment. Others will require total wellhead replacement. This paper will discuss results and recommendations on the report submitted. It will cover the integrity issues of old wellheads concerning safety, control, and effect of time on the equipment. It will also cover the operational issues on those wellheads that prevented safe and controlled workover operations. Improved technology was the ultimate solution, and a detailed comparison between the old and the new types of wellheads will be discussed in the paper.

"We Believe Contractors are our Partners in Business" Business partners carryout majority of our activities. Drilling is the most hazardous real estate on the earth. We do not differentiate Kuwait Oil Company (KOC) and Business partners while reporting HSE Statistics as we share their sorrow and happiness equally (Every incident occurs in any area of operation with our Business Partners is counted as KOC incident). We own and take the responsibility to investigate all the incidents and lessons learned are shared on weekly basis with all our Rigs & other groups of KOC to prevent recurrence of such incidents in future. COMMON HSE OBJECTIVES Effective coordination to create a better partnership Duty of Care demonstration by the leadership Improve the image of the company (Both KOC & Business partners) Compliance to HSE MS procedures of KOC and Business partners through proper bridging. As appropriate to the risks associated with drilling operations, the evaluation and selection process for the business partners shall consider the adequacy of their HSE Management practices, their HSE performance record and their ability to perform work in a responsible manner consistent with the KOC HSE Management System. Risk register is prepared to identify all the hazards and risks associated with the operations, camp and office areas and communicated to the business partners to consider during risk assessments at rig sites. This risk register is reviewed on yearly basis and/or whenever there is an occurrence of serious incidents in drilling operations. Appropriate recommendations will be captured in the risk register and addressed. We do identify the interfaces between KOC and our Business partners and effectively managed. KOC shall provide clear deliverables and performance standards like HSE KPIs shall be agreed and monitor compliance to the set KPIs on monthly basis and detailed review on Quarterly basis. Also we have a bridging document with the KOC and Business partners HSE MS to ensure both are in the same page when it comes to HSE Management. A training matrix is also provided in line with KOC HSE MS and business partners are advised to comply to the matrix and majority of the times they supersedes our requirements which is a good sign as we consider.

TX 75083-3836 U.S.A., fax 1.972.952.9435. AbstractThe Umm Gudair (UG) Field is located in West Kuwait and is managed by Kuwait Oil Company (KOC). With the aim of draining oil from the undrained northern flank of the west UG area, KOC decided to drill UG-132H, an openhole horizontal producer.UG-132H was chosen as the replacement well for an abandoned well. Located in the northern flank of the field, UG-132H was placed approximately 450 m west of the abandoned well. The lateral drain hole objective of keeping the well at a minimum of 65 ft above the oil/water contact was achieved.Executing this strategic well required careful selection of casing programs, drilling tools, services, and teamwork from all departments to keep the well within the desired target. To achieve the objectives, the KOC team decided to utilize an advanced proprietary rotary steerable system, logging while drilling (LWD) Imaging technology and the geosteering services to properly place the well within the reservoir. The steerable System enabled smooth and timely drilling of the drain hole. This resulted in a smooth and in-gauge borehole, hence producing a favourable environment for acquiring good quality real-time images for accurate structural dip determination and well placement. This paper will focus on the well profile, and the benefits of the advanced rotary steerable system for the long drain hole section. It will also highlight the complementary nature of transmitting both the density image and resistivity image in real time to enable accurate steering decisions. It will also show how the LWD images were useful in characterizing the different facies within the reservoir.

TX 75083-3836 U.S.A., fax 1.972.952.9435. AbstractThe Umm Gudair (UG) Field is located in West Kuwait and is managed by Kuwait Oil Company (KOC). With the aim of draining oil from the undrained northern flank of the west UG area, KOC decided to drill UG-132H, an openhole horizontal producer.UG-132H was chosen as the replacement well for an abandoned well. Located in the northern flank of the field, UG-132H was placed approximately 450 m west of the abandoned well. The lateral drain hole objective of keeping the well at a minimum of 65 ft above the oil/water contact was achieved.Executing this strategic well required careful selection of casing programs, drilling tools, services, and teamwork from all departments to keep the well within the desired target. To achieve the objectives, the KOC team decided to utilize an advanced proprietary rotary steerable system, logging while drilling (LWD) Imaging technology and the geosteering services to properly place the well within the reservoir. The steerable System enabled smooth and timely drilling of the drain hole. This resulted in a smooth and in-gauge borehole, hence producing a favourable environment for acquiring good quality real-time images for accurate structural dip determination and well placement. This paper will focus on the well profile, and the benefits of the advanced rotary steerable system for the long drain hole section. It will also highlight the complementary nature of transmitting both the density image and resistivity image in real time to enable accurate steering decisions. It will also show how the LWD images were useful in characterizing the different facies within the reservoir.