Identification of the source of pressure communication between well tubing-casing and casing-casing annuli presents an enormous challenge to petroleum engineers. Qatar Petroleum recently field-tested an acoustics based tool to successfully pinpoint the source of high pressure in the tubing casing annulus in a deep gas well in an onshore field. This paper presents a description of the technology and the findings from the field trial. An ultrasonic leak detection tool has been developed for down-hole applications to take advantage of the unique properties of ultrasound energy propagation through various media. This data acquisition equipment has been developed to allow continuous logging SRO (Surface Read Out) operation on conventional electric line or memory mode on slick line. The movement of fluids across a failed barrier creates turbulence which in turn creates ultrasonic frequency sound waves that are detected by the tool sensor. This new tool is different from the conventional noise logs as its' highly customized multiple sensitivities enable the detection of leaks as small as 0.02 Litres per Minute (LPM) with an accuracy of inches in the production tubing, casing and other completion equipment. It is also practically immune to disturbances from distant noise sources. The tool was run in a deep gas well with a history of high pressure in the tubing-casing annulus. Diagnostic work prior to the trial had established that the wellhead seals were not the source of the pressure. A leak rate of 3.5 LPM was estimated based on the pressure build-up trend in the annulus. The paper describes the procedure for running the survey and discusses the interpretation of the results that confirmed a casing leak at a failed recirculation valve (DV). The field trial confirmed that ultrasonic based well leak detector can accurately and efficiently detect very small tubing and casing leaks. Introduction: A growing concern in the life of an oil or gas well is the pressure buildup in its annuli. The first challenge for a petroleum engineer is to identify the source of the leak to enable design of an effective remedial activity. There are many methods to identify the source of leaks in a well. The simplest, cheapest and most common is the "Pony Tail" method. If the leak is big enough (>100 LPM), flowing from the tubing into the A-annulus then a highly experienced slickline operator running a "Pony Tail" assembly may be able to detect the leak location. This method will, obviously, not work with very small leaks. More advanced technologies have been used over the years to identify such leaks more accurately. Over time, a philosophical approach has been used to decide what technological gadget to use. Temperature logs, spinner logs, downhole cameras, and noise logs, etc. or a combination thereof can help identify rather small leaks (with leak rates varying between 10 LPM and 100 LPM) between the tubing and A-Annulus. The optimal tool string depends in part on the magnitude of the leak. At the lower range of leak rates, the noise log is often the most sensitive. The temperature log works over a broader range of leak rates, but is usually not as sensitive as the noise log. A spinner can be used for higher leak rates.2 The problem becomes more complicated when the leaks are caused by packer (seal element) failure or holes in the casing causing fluid movement from the B-Annulus to A-Annulus, or fluid movement from the formation through the annuli and reaching to the A-Annulus. (i.e. problems behind the tubing wall). Matters are further complicated if the leak rate at the time of investigation is lower than the sensitivity of the tool being used for identification. Based on extensive R&D in the ultrasound technology domain, it was discovered that an active leak at rates ranging from 0.02 LPM to 150 LPM would create turbulence with a high frequency wave that would generate an ultrasonic signature.

As part of the ADNOC's strategic approach to maximize the value of procurement, a Group Category Management initiative was launched for Electric wireline logging services with a primary objective to leverage the spending and volume of ADNOC Group Companies. In support of this direction, ADNOC sets the following goals; ADNOC to become the regional operator of choice, securing Gulf Countries Council (GCC) Wireline service capacity to ensure tool and personnel availability, implementation of log output-based scope design, promoting operational delivery through the introduction of performance-based work incentives, reducing operational delays and Non-Productive Time (NPT) through improved supplier performance management, increasing access to new technology, promoting In-Country Value (ICV), and increasing Emirate employment in Wireline Logging. ADNOC Upstream operating units execute oil and gas drilling and production operations that spread over onshore and offshore Abu Dhabi and handle various reservoir types and conditions such as shallow/deep reservoirs, sweet/sour, and ultra-sour gas reservoirs. Under such circumstances, a critical success factor of this initiative was underpinned by a unified scope of work that accommodates Onshore/Offshore, sweet, and harsh operating environments to come up with a scope that balances the work environment requirement, service quality, and cost. This paper describes the detailed journey to build a joint scope of work that can serve all ADNOC operating units in a cost-effective and flexible model based on the building blocks concept. To compartmentalize, ADNOC technical team built the scope package and respective cost model based on service type that includes Open Hole, Cased Hole and Explosives logging services. The proposed scope of work model was tested by designing different types of jobs. Later, a technical group verified the proposed model by comparing the model outcome with the current discrete models for Onshore, Offshore, harsh, and extended reach well environment. It was concluded that integrated scope of work is a safe, robust, and cost-effective model that assures the same level of service quality is provided all over Group companies considering the differences in operation environment and requirements. Following the scope and strategic option review, a group level procurement event was determined as the best course of action to achieve the set objectives. As such, a market capability assessment and demand analysis were conducted to initiate the sourcing event.

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The detection of the source of communication and pressure build up in the first or second annuli presents a huge challenge to the industry. Dubai Petroleum has been utilizing an acoustics based logging tool to pinpoint the source of high pressures in the annuli of its gas lifted oil producers and water injectors in its offshore operations. This paper presents a description of the technology and the findings from Dubai Petroleum's experience on several case histories. An ultrasonic leak detection tool has been developed for down-hole applications, to take advantage of the unique properties of ultrasound energy propagation through various media. This data acquisition equipment has been developed to allow continuous logging operation on conventional electric line cable or memory mode on slick line. The movement of fluids across a failed barrier creates turbulence creating high frequency ultrasound waves that are detected by the tool sensor. This new tool is different from the conventional noise logs as its highly customized multiple sensitivities enable the detection of leaks as small as 0.02 Liters per minute with an accuracy of 1 Inch in the production tubing, casing and other completion equipment. It is also less prone to disturbances from distant noise sources. The successful experience gained by Dubai Petroleum in utilizing this technology has confirmed that ultrasonic based well leak detector technology can accurately detect very small tubing and casing leaks. Introduction: The challenges related to well integrity issues are a major concern in a growing inventory of aging wells all over the world. Interventions to repair the leaking wells or closing and abandoning wells have led to high operating cost, low overall oil recovery, and in some cases unsafe operation. The reasons why leakages occur can be different, and finding the causes is a very complex task. Internal and/or external corrosion is probably the most common cause of leaks in aging wells completions. The varying stress/strain regimes a well is subjected to during its service life can lead to failure of one or more of its safety critical elements: tubulars, production packers, down hole safety valves, SSDs, mandrels etc.

The ability to intervene in extreme extended reach wells using conventional technology has lagged behind the ability to drill and complete them. This paper intends to describe how the physical properties inherent in carbon composite materials provide a means of deploying logging tools into such a well in combination with a high-performance tractor, and to document a case study where a total depth of 40,600 feet (ft) was achieved against a production flow of 6,500 barrels of oil per day (BOPD). Extending the distance that a toolstring may be conveyed into a horizontal well by means of tractoring devices is well established. The medium for the conveyance becomes the critical component of the system to both maximise the ultimate depth achievable and to ensure safe retrieval. Low friction, low weight and high strength of the rod all combine to reduce required tractor loading and ensure safe recovery. The rod rigidity confers exceptional depth accuracy and removes the potential of tool-lift at high production rates, allowing logging under conditions that are truly representative of commercial well operation. A well that was drilled to a depth in excess of 40,000ft measured depth, with a trajectory designed to maximise the contact between wellbore and reservoir, was completed with a limited entry liner. A total of 37 compartments with lengths between 700ft and 900ft were separated with swell packer assemblies along a horizontal section of 25,000ft. Critical information about the production flow, including toe/heel balance, had been unavailable because of the limitations imposed by the available intervention methods. The intervention was designed to fully exploit the physical properties of the carbon composite rod in combination with the most efficient in-well controlled tractoring technology available, and aimed to reach deeper than 40,000ft. Simulations based on previous experience showed that this depth would be achievable with the tractor chosen and further that this could be achieved even with the well flowing at rates of over 5,000BOPD. This meant that deferred production could be minimised along with waiting periods for flow stabilisation. The intervention was successfully concluded in a single operation, gathering production data from as deep as 40,600ft. Performance of both rod and tractor aligned with planning simulations with significant margin, indicating further performance enhancements in reach being readily achievable. Drilling of such extended reach wells from existing islands will reduce well counts, accelerate development and increase oil recovery by unlocking reserves from the tight rock and areas that are currently unreachable from existing islands and wellhead platforms. Technology solutions like carbon composite rod and high-performance tractors enable the operators to acquire production logs & perform well services effectively to maintain the life cycle of extended reach wells inaccessible with conventional solutions.