In the recent past four shallow wells were drilled in the Ahmadi Area and the purpose of these wells was to observe the fluid movement in these wells, either to the surface or communication between the zones in the down-hole. These unconventional wells were designed for unrestricted inflow of fluids into the wellbore as appreciable commercial flow was never expected. The challenge was also to log the flow and pinpoint the fluid entry points. Conventional PLT tools were not suitable as spinners threshold velocity could not be achieved in such feeble flow. Research was done to find the most suitable tools and equipment that are available in the industry and most useful to this project at very shallow depths and in real-time monitoring. It was decided that the minor temperature variation against the contributing zone could be captured real-time by DTS (Distributed Temperature Sensors) and Permanent Down-hole Gauges will give the real-time pressure and temperature readings at the point of its installation in the wellbore. These data can be analyzed to quantify the flow contribution and fluids entry points. At this shallow depth the effect of diurnal temperature change was also a main factor. The DTS and Permanent Down-hole Gauges were installed in all 4 wells, 3 of these are 250’ deep and the fourth well is 1000’ in depth. The performance of these tools gave very distinctive results that benefitted in the investigation of the fluid movement in these wells and in the surrounding. This paper and presentation will show the details of this project for the 4 wells and the installation and performance of these tools and how it benefitted the project. The real-time monitoring of these data and the challenges encountered will also shared.

The Passive Inflow Control Device enhances the well productivity and recovery by removing Heel to Toe effect in a homogeneous reservoir and allowing production optimization along the entire horizontal section in case of heterogeneous reservoir. But these ICDs have their own limitations in controlling the high water producing zones in horizontal wells. The introduction of Sliding Sleeve Technology in horizontal wells has added a greater value to ICDs by further controlling water production from undesired zones. The new Advanced Inflow Control Device with sliding sleeve approach is built upon the usefulness of sliding sleeve technology in horizontal wells. This rigless technology can be used to maximize oil production from horizontal wells, save huge rig workover cost and extend the economic life. This paper describes a case study in Greater Burgan Field showing the challenges encountered while drilling the horizontal well and benefits associated with the integration of the passive Inflow Control Devices (ICD) with Sliding Sleeves in complex horizontal wells. After the well was put on production, Production Logging Tool (PLT) was run to identify the high water producing compartments and accordingly plan was made to close these ICDs by mechanically shifting the sliding sleeves. Pre and post DTS survey clearly confirmed the successful closure of high water producing ICDs. Several flow tests were done before and after shifting the sliding sleeves to monitor the reduction in water cut. A complete case study is presented to permit the readers to know the benefits of using sliding sleeves along with ICDs in horizontal wells and thus improve the hydrocarbon recovery. Leveraged knowledge from this pilot has provided an insight into the capabilities of sliding sleeve type of ICDs.

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As part of KOC strategy to develop the technical skills of the new recruits this paper will present a series of best practices related to decision workflows during drilling of horizontal wells through a recognized multidisciplinary team which optimized the preparation level and knowledge standard for the young generation through practical workshop and in short period. The best practices identified included aspects related to reservoir management, location selection, subsurface characterization and drilling specifics. Those were the key elements in the preparation of the technical training with the support of a multidisciplinary team that proved beneficial to the decision processes and issues faced during drilling in real time workflows. However optimization of a well needs skill, knowledge, right vision and experience, hence the results of the extensive drilling campaign and different cases of horizontal wells allowed the establishment of a practical training workshop protocol using actual acquired data for the planning, follow-up and assessment of drilling operations, which is now used in Fields Development South and East Kuwait. The practical workshop encompassed two case histories of horizontal wells where good decision procedure resulted in avoiding complications during drilling and effectively optimized most of the drilling path. This practical, interactive workshop was successful in developing with an integrated framework, the necessary skills in the participants, in all technical disciplines involved, namely Geosciences, Petroleum Engineering and Reservoir Engineering, in a pioneer effort of the Greater Burgan teams, not used before in KOC for training. The impact of this workshop was to enhance the experience of the young professionals in Petroleum Engineering, Geoscience interpretation and Reservoir Management, as well as to build their integrated knowledge on horizontal drilling for the benefit of KOC, across all Directorates and possibly applicable to other oil companies.

The multilateral well technology was used for the first time in Albian Third Sand reservoir of the super-giant Greater Burgan Field of Kuwait. The reservoir is on production for more than 60 years with conventional development techniques. The multilateral drilling technology was adopted particularly for exploiting the heterogeneous and complex units within Third Sand Upper member of Burgan Formation. The Third Sand Upper (3SU) unit came up as the right candidate because of its low thickness, relatively poor reservoir quality and inconsistent occurrence rendered it difficult to exploit by conventional wells. On the contrary the more prolific Third Sand Middle unit (3SM), was not considered for multilateral drilling because of its massiveness and hydrodynamic connectivity. Nodal Analysis results suggested comingled production from 3SU and 3SM as not suitable, because of high pressure differential and permeability contrast. The 3SU was deposited in a broad transgressive set up. As expected in such transgressive units, the sands are thin, heterogeneous and discrete in nature. Paleogeography and sand thickness maps helped in understanding the geometry of the sand bodies for suitable placement of the laterals. A pre-drill model was built based on the logs of the nearby wells to predict the facies in the laterals. Two stacked bilateral wells were drilled to drain different layers in two separate locations. Multilateral TAML-4 level was selected for adequate junction stability and options for possible re-entry. The lateral length varied from 650 to 1663 ft depending on the spatial distribution of the sand bodies. Effective geosteering through 5 to 10 ft thick sand layers in these wells encountered 0.5 to 1.5 Darcy reservoirs. These thin, discontinuous layers produced about 3000 to 5000 BOPD on production testing, thereby increasing the expected productivity six fold compared to vertical wells. The success obtained in producing from these thin, heterogeneous and otherwise under exploited reservoirs will open up new fundamentally different and improved development opportunities Introduction The Greater Burgan Field located in Southeast of Kuwait (Figure 1) is a north-south trending anticline, and covers an area of about 450 square mile. It consists of three three major fields, Burgan, Magwa and Ahamdi with hydrocarbon contained in three major reservoirs namely Wara, Burgan and Maudud (Lower Cretaceous) and two minor Jurassic carbonate reservoirs Minagish and Marrat (Figure 2). The Burgan field was discovered in 1938 and went on production in 1946. The first wells drilled in Magwa and Ahmadi were in 1951 and 1952 respectively. The Greater Burgan Field is the world's largest siliciclastic oil field which is on production for more than 60 years. In Greater Burgan Field, the principal producers are the Burgan and Wara reservoirs. Its primary producer is the Third sand middle 3SM unit which contributes a major part of the total field production.