Search citation statements
Paper Sections
Citation Types
Year Published
Publication Types
Relationship
Authors
Journals
In order to carry out the first HPHT field development offshore in Malaysia, learning from experience of HPHT operators in the North Sea, a detailed focus on lifecycle and well integrity aspect has been thoroughly emphasized throughout the well delivery phase. At an initial stage in the project, a locally conventional initial design considered the use of TCP to perforate a 7″ liner and then complete the well in open hole with overbalanced completion fluid. This solution carried several challenges that would have affected the safety of the completion process and the future integrity of the well architecture. A different approach, in which a fully cased hole well is completed in underbalance and then perforated once the completion is installed and tested is introduced for the first time within PETRONAS. The system allowed the perforation of a 400m HPHT reservoir interval in a single run, by using a dedicated coiled tubing deployment system. The implementation of this completion philosophy permitted to achieve the following milestones: Completion in underbalanced packer fluid, which enhanced the well architecture by reducing potential production casing failure due to extreme loads in case of tubing leak.The use of inhibited fresh water, provided an effective, alkaline fluid that eliminates the very high potential for corrosion created by heavy, high halides completion brines.Safer way to run the completion in a closed, inflow tested environment.Single perforating run, which allowed for a safer procedure for the deployment of guns. There is no deployment of guns under pressure or under exposure to hydrocarbon.If required, especially in very tight reservoirs, there is the ability to displace the well with N2 immediately after perforating (separate runs for stimulation are not required)As soon as the last gun is out of hole, the well is ready for well testing / clean out / production. This paper covers the design, QAQC, operational and logistics aspects of the KN Ultra Deep'sCoiled Tubing Conveyed Perforating with a final section covering the challenges and lessons learned that may be used by project teams in the future.
In order to carry out the first HPHT field development offshore in Malaysia, learning from experience of HPHT operators in the North Sea, a detailed focus on lifecycle and well integrity aspect has been thoroughly emphasized throughout the well delivery phase. At an initial stage in the project, a locally conventional initial design considered the use of TCP to perforate a 7″ liner and then complete the well in open hole with overbalanced completion fluid. This solution carried several challenges that would have affected the safety of the completion process and the future integrity of the well architecture. A different approach, in which a fully cased hole well is completed in underbalance and then perforated once the completion is installed and tested is introduced for the first time within PETRONAS. The system allowed the perforation of a 400m HPHT reservoir interval in a single run, by using a dedicated coiled tubing deployment system. The implementation of this completion philosophy permitted to achieve the following milestones: Completion in underbalanced packer fluid, which enhanced the well architecture by reducing potential production casing failure due to extreme loads in case of tubing leak.The use of inhibited fresh water, provided an effective, alkaline fluid that eliminates the very high potential for corrosion created by heavy, high halides completion brines.Safer way to run the completion in a closed, inflow tested environment.Single perforating run, which allowed for a safer procedure for the deployment of guns. There is no deployment of guns under pressure or under exposure to hydrocarbon.If required, especially in very tight reservoirs, there is the ability to displace the well with N2 immediately after perforating (separate runs for stimulation are not required)As soon as the last gun is out of hole, the well is ready for well testing / clean out / production. This paper covers the design, QAQC, operational and logistics aspects of the KN Ultra Deep'sCoiled Tubing Conveyed Perforating with a final section covering the challenges and lessons learned that may be used by project teams in the future.
The development of light-oil reservoirs in Kuwait has become increasingly more important for maintaining the quality of exported crude. This is due to the fact that producing light-oil reservoirs has proven to be not only a necessary link for maintaining the oil production from this area but also for increasing it. As a result, efficient testing of the light-oil reservoirs has become paramount in importance for overall well and field development. The reservoirs in Kuwait are low permeability, high pressure/high temperature (HP/HT) and sour. In earlier wells, the strategy had been to perforate these formations balanced or slightly overbalanced, in mud, with through-tubing guns. Results from testing in several wells indicated that if they could be perforated under-balanced, the formations would yield better results since this method would allow better penetration and perforation cleanup. A number of reservoirs are stacked horizontally and range from typically conventional to fractured limestone. In view of the corrosive nature of the fluids present, one of the primary efforts in the testing of these wells had to be directed toward keeping the number of wireline and coiled-tubing operations to a minimum without compromising the testing objectives. Since it was necessary to test multiple objects in the exploratory wells individually, special effort was focused on determining methods that could effect a reduction in the testing period for each object. By reducing individual testing times, Kuwait Oil Company felt that the overall savings would be significant. Several areas were identified that would require special consideration. This paper will discuss these areas (listed below) and how the challenges they presented were addressed:Modifications to retrievable completion test (RCT) tools and tubing-conveyed perforating (TCP) equipment that would be required to test these zones efficiently.The challenges associated with designing and carrying out the tests.Ongoing modifications in the testing methodology to overcome the testing challenges.The operation of the test-string, annulus-pressure-responsive components in the heavy oil-based mud and the difficult wellbore conditions.How the problems of shaped charge performance in the naturally fractured formations with unusually high compressive strength and very low matrix permeability and porosity were resolved. The modifications to tools and methods allowed the goals of the operator and service provider to be met. Background Fig. 1 shows a typical completion schematic for the formations intercepted in the deep Jurassic layers of west Kuwait. Monobore completions are normally used. The reservoir evaluation technique followed by the Kuwait Oil Company in the wells of west Kuwait follows:Drill and complete well in the zone of interestMobilize and rig-up wireline perforation unit and production testing spreadPerforate the well using through-tubing guns with mud capsFlowtest the well through the production testing unit on location. While the above procedures were satisfactory, it was felt that that better well performance and completion efficiency could be achieved by a step change in the formation evaluating technique. Other options were reviewed.1,2,3 The first change planned was to test the well using a retrievable completion test (RCT) string. The reasons for making this change were due to the testing methodology adopted and the changes made to the procedural operations. These changes follow:Since the wells were deep with a telescopic casing design, and the reservoir was sour, the decision was made to test using completion tubing instead of the drill string.A Christmas tree was to be used as opposed to a surface test tree with testing performed through the blowout preventers (BOPs) as in a regular test. Safety was the primary driver for using a Christmas tree as the well had H2S and high pressures.
fax 01-972-952-9435. AbstractUnderbalanced drilling (UBD) technology has been gaining in popularity around the world because of its capability to reduce or eliminate formation damage, to increase production rates, and in some cases, increase the volume of recoverable reserves. The technology is applicable to fields where formation damage is a concern or where problems such as severe fluid loss, differential sticking, steering problems or slow drilling rates are encountered with conventional drilling.With underbalanced drilling, the formation pressure is greater than the hydrostatic pressure, allowing hydrocarbons to flow into the wellbore during drilling. This prevents potentially damaging drilling fluids and drilled fines from penetrating the producing formation.In previous experiences in the field using traditional drilling methods, considerable formation damage had been experienced, and although UBD had never been attempted in the area before, Brunei Shell Petroleum and its government partner decided to use this technology in a three-well trial in the Rasau field, located onshore in Kuala Belait, Brunei.Of the three wells attempted during this UBD trial one well could not be drilled due to catastrophic borehole collapse. The other two wells were successfully drilled to depth using UBD techniques; however, multiple hole volumes of solids were produced during drilling and production testing, indicating borehole stability problems.Production rates observed after drilling to TD and prior to running completions indicated zero formation impairment, with well productivity exceeding expectation; however, during the completion phase, mechanical problems occurred, and post completion well tests indicated productivity reductions of 60 to 70% compared with the pre-completion tests. This paper discusses the planning, drilling, results, highlights, and lowlights from this UBD trial, along with learnings and recommendations for future application of the technology.The execution of the program led to a sharp learning curve, and the development of recommendations that can be applied to future operations in this field. These primarily relate to well (construction) design, drilling procedures, equipment design, rig-up and rig-down optimization between wells, and completion design.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.