Horizontal wells are well-recognized as one of the most effective innovations in exposing the wellbore to maximum reservoir contact and drainage area to improve recovery economics. It creates lower pressure drop to achieve better productivity compared to vertical/deviated wells. In order to enhance sweep efficiency, horizontal wells can be completed with Inflow Control Devices (ICD). ICD completion creates a more uniform inflow distribution along the production interval of the horizontal well. It aims to delay water breakthrough at high permeability zones and to provide better well clean up at initial production. In general, the performance evaluation shows that horizontal wells with ICD's have better sustained productivity than horizontal wells completed open hole or with screens. ICD completion design was previously done based on near-wellbore data only. A new methodology has been applied by tailoring the ICD completion design with fine-grid dynamic 3D simulation that is fast enough to be used for real-time model optimisation while drilling. 3D simulation enables the optimisation for the number and placement of nozzles and packers by maximising the utilisation of reservoir information. The improvement on delivering ICD completion design also includes torque and drag analysis on every horizontal well candidate. The new ICD completion design workflow has been applied since 2015. The real-time single-well dynamic 3D simulation-based design results in a better understanding of the completion options and their performance predictions. Various ICD completion scenarios, from constant nozzle sizes to varying nozzle sizes, and different packer numbers and placements are simulated. The new 3D simulation tool is able to provide time-lapse effects of cumulative fluid (oil and water) production for different flow rates. Additional pressure drop across the completion is modelled for different nozzle configurations. Based on these simulation results better informed decisions can be made regarding the nozzle sizes and numbers. In addition, the proposed ICD completion run-in-hole tally is evaluated in the torque and drag simulator to ensure the proposed ICD completions can be run to total depth (TD). The results of these two simulation steps are combined to optimize the final ICD completion design.

A great deal has been published in recent years regarding horizontal well technology. However, little has been pub-lished concerning high rate acid stimulation treatments in openhole sections in horizontal wells. In fact, several articles suggest that a lateral section must be cemented and cased for the appropriate zonal isolation.1 This paper is a case history of a lateral openhole completion which utilized a high rate acid stimulation, polymer gel blocks for diversion, and dynamic spectral gamma ray log analysis. The Keystone Cattle Company Well No. 378-H, located in Winkler County, Texas was completed in the Wolfcamp Formation of the Flying "W" Field. The completion interval consisted of 1388 ft (423 m) of lateral, openhole section. A 200,000 gal (757 m3) multiple stage, foamed nitrogen acid stimulation was performed using polymer gel blocks for diversion. Five of the acid stages were tagged with three different radioactive isotopes. A spectral gamma ray log was used to identify the treatment intervals during the stimulation to effectively displace the polymer gel blocks. This paper includes background on the well and objectives for the completion techniques used. The detail procedure and evaluation of the real-time pressure and logging data are also discussed.

Horizontal well technology has been used in the Pattani Basin to target oil and gas reservoirs since the late 1990’s. As of today, the Chevron Operated B8/32 block and Platong fields have been producing from 70 horizontal wells. While about 80 % of the horizontal wells in Platong have been completed barefoot, the use of ICD’s has been increasing since 2010. Recently, in the Platong field, two ICD equipped horizontal wells were used initially for primary production of a major reservoir, following which one of the two wells was converted into a water injector to enhance total recovery from the reservoir. The ‘Z’ reservoir located in Platong field has significant barrels (in the millions) of oil in place with an initial gas cap and a water leg. The reservoir was initially appraised and tested with a single deviated wellbore. This well confirmed the reservoir potential and identified gas and water coning, together with sand production as the major risks to optimising oil recovery. To manage potential oil and gas coning, a reservoir development plan, based around a pair of horizontal well completions, was developed. Both well completions were designed with sand control screens incorporating ICD’s to optimize inflow along each horizontal wellbore. The wells were drilled and completed in early 2012. After collecting surveillance data and modeling the primary production performance of the reservoir, a waterflood opportunity to increase total recovery was planned. The asset team implemented the in-situ conversion of one of the horizontal wells into a waterflood injector in August 2013. Response to the water injection has been confirmed in the second well of the pair and incremental oil of >50 MBO has been recovered. This case study presents an analysis of the target reservoir, the development strategy and then captures the lessons learned from the performance of horizontal producers with ICD completions during primary production and during the later waterflood phase. The main challenges for future horizontal wells applications in Platong are relatde to thin fluvial sands and depletion. The use of ICD’s will continue to be proposed for new horizontal targets based on the positive incremental production impact.

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Lake Tuscaloosa, created in 1969 by the impoundment of North River, provides the primary water supply for Tuscaloosa, Alabama, and surrounding areas. This report describes the rate of sedimentation in the lake from its principal tributaries.The rate of sediment deposition in the lake is low. The maximum sediment deposition from 1982 to 1986 at 17 lake cross sections was about 3.5 feet (or 0.9 foot per year) at a cross section that received drainage from Brush Creek basin. Brush Creek is an unmined basin with steep overland and channel slopes.At 15 of the 17 cross sections, the maximum sediment deposition was less than 2 feet (or 0.5 foot per year). Scour and fill processes (redistribution of the sediment) appear to be taking place at many of the cross sections.