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.

The Greater Burgan Field consists of three sub fields (Ahmadi, Burgan and Magwa). Drilling commenced in this field in 1938 and it went on stream in 1946. Most of the production comes from a giant oil reservoir in a siliciclastics depositional environment. This giant oil reservoir has intercalating sand shale sequence with the upper part having mixed lithology. Co-existing together are argillaceous glauconitic sandstones, calcite, dolomite and anhydrite with pyrite and siderite. With increasing demand of oil in the world, it has become necessary to improve oil production. As a result, the various field development assets of Kuwait Oil Company (KOC) are tasked to increase the number of horizontal wells in order to access thin reservoirs in the field. This has prompted these teams to increasingly rely on Logging While Drilling (LWD) services as well as improved geosteering practices in order to efficiently access the untapped energy resources buried several thousand feet below the earth's surface. Evaluating these wells becomes an issue especially if the wells are drilled in areas that might add to the reserves of the asset. Resistivity anisotropy is a major issue, especially if it occurs with influence of other bed boundary effects like resistivity of adjacent beds or polarization horn effects. Water coning issues in the field makes it even worse to interpret the resistivity data as they become spiky. Complexity of the resistivity signature in a mixed lithology environment makes petrophysical evaluation difficult. With the recent introduction of the Multi-Function LWD tool where most of the basic measurements are collocated in one LWD collar, it is now possible to make measurements with similar environmental influence prior to significant invasion of the formation. In addition, the introduction of capture gamma ray spectroscopy and formation sigma in real time has improved the petrophysical evaluation of this complex resistivity environment with mixed lithology in wells that are difficult or even costly to consider wireline logging. This paper aims at highlighting horizontal well drilling issues occasionally encountered in the Greater Burgan Field and the recent introduction of the Multi-Function LWD service to help address these formation evaluation issues.

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TX 75083-3836, U.S.A., fax +1-972-952-9435. AbstractThe Wara Sandstone reservoir in the Minagish Field of Kuwait Oil Company is a complex deposition of a typical pro-deltaic environment. The sedimentation starts from tidal marine deposition containing beach sands and lagoonal facies that are subsequently overlain by fluvial channel sands. The bases of the channel sandstones have in many cases an erosional contact that cuts into the underlying sequence. The marine sandstones are of much finer grains and poorer quality than the overlying channel sands that are generally coarser in grain size, thereby having better porosity and permeability. On top of the channel sequence, a marsh overbank or lagoonal environment overlay and are characterized by silts and coaly layer sequence. They are also finalized by a subsequent deposition of progradational coastal marine silts and fine sands. All these deposits find their high stand in the overlying Ahmadi formation.The sediment sequence is repeated up to four times and zero to four channels may develop and intercepted by drilled wells depending on the well location within the field.Within this channel sand bodies are different lobes that contain varying degree of minerals from glauconite to anatase, pyrite and hematite with other cement materials like calcite. The matrix materials in the more shaly intervals are predominantly illite and glauconite. Glauconite occurrence was either deposited via transportation (detrital) or generated during early diagenesis to act as cement materials. Glauconite cement has a strong impact on reservoir producibility and since it is present throughout the entire sequence of depositional events, it plays a great role in the petrophysical evaluation of the reservoir.Being able to geosteer within the sand bodies will require proper understanding of the depositional environment and thus requires discriminating intervals with relative abundance in glauconitic grains as they impact reservoir quality.It has been proven from previous core studies that the more the detrital glauconite occurrence, the greater is the relative abundance of glauconite cement as well. In this paper we propose the use of increase in the presence of iron (Fe) dry weights with its associated Titanium from the multi-function logging while drilling (LWD) tool to discriminate the relative abundance of glauconite in the reservoir sand bodies, thereby characterizing the lobes. We will also highlight the benefits derived from using the formation sigma in real time for petrophysical interpretation and its usefulness in deciding intervals to perforate in horizontal well drilling.