In 2016 BP adopted a technology plan to investigate how efficiencies could be realized in the inspection area. The project termed UWIP (Under Water Inspection Program) was divided into two areas: Alternative inspection technology, Advanced inspection technology.
Alternative Inspection technology addresses the configuration of existing technology to deliver efficiencies
Advanced Inspection technology looks to near future opportunities that may be realized within a 5-year period.
This presentation primarily addresses the Alternative agenda, with focus on how the configuring of sensor packages onboard a variety of underwater vehicles has delivered data up to 8 times faster than traditional inspection methodologies. Termed FDII (Fast Digital Imaging Inspection) the concept aims to replace video with Laser / Stills and contact Cathodic Potential systems with Field Gradient.
The Advanced agenda presents BP progress in delivering unmanned, automated Unmanned Surface and Underwater Vehicle Systems into Inspection programs.
BP has undertaken three FDII campaigns, 2017/18 in North Sea and 2018 Trinidad, inspecting 825 pipeline kilometers. There are another two FDII programs scheduled in North Sea and Caspian regions in 2019. Data acquisition has significantly increased; however, data management techniques have had to be reviewed and adapted. Inspection and integrity contractors expect to receive data in traditional formats and their systems (as well as operators) are not configured to receive and interpret the new FDII data. Additionally, software houses are also behind the curve in allowing users to host and deliver to stakeholders.
FDII facilitates rapid data acquisition and operational teams are ready to grab credit for efficient execution. But data bottlenecks in editing, eventing and delivering data to stakeholders have removed some of the ‘shine’ from the project. For FDII to develop a step change is required in the data management.
FDII is a technique, it is not an inspection criterion. FDII lends itself to Fast ROV and AUV underwater vehicle developments which are also linked to operation from Unmanned Surface Vessels. BP has a stated goal that by 2025 all inspections will performed from unmanned systems. FDII is a technology that progresses us to that goal.
The Hook-up and Commissioning program for the BP operated Clair Ridge facility was conducted over a period of three years, starting with the accommodation platform in 2015/16, and then the Production and drilling platform over 2017 and 2018. The total topsides weight is 53,000 tonnes, and the field is located in the harsh waters of the Atlantic West of Shetland. Typically 750 persons were based offshore, but over the life of the program some 7000 individuals worked offshore at some point on the project. Recognizing the safety leadership challenges with such a major hook-up and changing workforce a huge amount of effort went into preparation and working with our contractors to onboard the workforce. Over the first months of the campaign the safety metrics were healthy and there was a good reporting culture, however an increase in incidents was seen, including one late in 2015 where a medical evacuation was required from the platform. The individual made a full recovery and returned to work however it caused the Operator and Contractor project leaders to reflect on their safety leadership and how they were working with and engaging with the workforce. It was a catalyst for change as the team was determined that no other serious incidents would happen during the project delivery.
In this paper we will share the Clair Ridge safety leadership journey and the steps taken by the operator, with the support and collaboration of the main contractors, to set a new approach to safety through the development of a genuine Culture of Care. This included: Building of trust and credibility between leadership and the workforce Leadership openness and transparency in communication Empowering front-line supervision to be safety leaders and giving them the skills and tools to do this well
Building of trust and credibility between leadership and the workforce
Leadership openness and transparency in communication
Empowering front-line supervision to be safety leaders and giving them the skills and tools to do this well
As a result of the approach the Clair Ridge team is proud that, in the three years since the incident in 2015, over 9 million offshore workhours have been completed without any other Lost Time Incident, and a safe start-up was achieved with no process safety related incidents. Clair Ridge realised some of the highest participation in safety observations and near miss reporting across the Operator's global projects portfolio, a continual and significant reduction in all injuries and benefited from an excellent reporting culture.
A Culture of Care has been owned by all, and been recognised and commended by the contractor workforce and visitors to Clair Ridge.
Brines are preferred to solids-laden fluids for completion operations due to their solids-free nature, which helps preserve formation permeability. Salt selection is mostly driven by the density that must be reached to match downhole pressure requirements. When density must be above 14.2 lbm/gal (1.7 s.g.), and crystallization must be prevented, previous options were limited to calcium bromide brines, zinc bromide brines and cesium formate. These brines have severe limitations: zinc brines can be harmful to oilfield personnel and the environment, cesium formate brines are cost-prohibitive and not readily available and calcium brines cannot meet deepwater crystallization requirements. A new brine technology has been developed, that is zinc-free and extends the density of conventional bromide brines beyond their theoretical limits. This new technology addresses the limitations listed above, while providing low True Crystallization Temperature (TCT) and Pressurized Crystallization Temperature (PCT) to perform in deepwater and cold weather applications.
The goal of our work was to maximize gas production and recovery from a horizontal appraisal well in the Mancos shale in New Mexico. This required a fracture design that would maximize perforation cluster efficiency and a lateral placement strategy that would maximize gas recovery. A key challenge was to design a fracture treatment that would overcome the extreme stress shadowing effects. Another key challenge was to optimize the lateral placement balancing multiple factors.
Fracture treatment simulations were completed for various designs. Fracture simulations indicated cluster efficiency could be dramatically improved by optimizing the way we pump the pad. A step-up technique for increasing pumping rates during the pad stage helped to initiate more fractures. Intra-stage diversion was utilized. Fracture simulations were performed to optimize the lateral placement. This required balancing multiple factors to access the highest gas-in-place (GIP) interval yet facilitate more fracture initiations per stage.
Fracture descriptions from the fracture simulations were input to a reservoir simulator to determine the optimal design. This paper will focus on the hydraulic fracture modeling.
This appraisal well was the most productive Mancos gas well ever delivered in the San Juan Basin. The 9,546’ lateral produced at a choke constrained plateau rate of about 13 MMscfd for 7 months and produced over 6 BCF in the first 20 months. A radioactive tracer log indicated an overall perforation cluster efficiency of 83%, a significant achievement in a shale with high stress shadowing.
The fracturing fluid design, diverter design and pumping techniques can be applied in many other shales as a low-cost way to increase perforation cluster efficiency, which will in turn result in higher production rates and higher cumulative recovery. Building on the success observed in the Mancos wells, BP and BPX Energy have subsequently utilized these techniques in other shale plays with success.
The concepts and workflow used to decide the optimal lateral placement is a well-defined approach that can be applied to other unconventional wells to increase hydrocarbon recovery.
Multistage hydraulically fractured horizontal well completions have come a long way in the last two decades. Much of this advancement can be attributed to the shale gas revolution, from which numerous transformational tools, techniques, and concepts have led to the efficient development of ultralow-permeability resources on a massive scale. Part of this achievement has been through a widespread trial and error approach, with the higher risk/failure tolerance that is a trademark of the statistical nature of the North American unconventional resource business. However, careful consideration must be taken not to blindly apply these techniques in more permeable tight gas formations, which often cover an extensive range of permeability. Inappropriate application can compromise the effectiveness of the hydraulic fracture treatment and impair long-term well productivity.
Khazzan is a tight to low-end conventional gas field in the Sultanate of Oman, with low porosity and permeability in comparison to conventional formations. The target formations comprise extremely hard, highly stressed rocks at high temperature. The development strategy included vertical wells with massive hydraulic fracture treatments and multistage fractured horizontal wells. The former has been largely successful in the higher-permeability areas, and the economic transition from vertical to horizontal well development, based on rock quality, is continuously evolving. Compared to the rapid learning curve achieved through the more than 80 vertical wells drilled to date, fewer horizontal wells have been drilled, and, as a result, the understanding is still relatively immature.
The paper outlines the technical and operational journey experienced in horizontal wells, to prepare the wellbore and ensure a suitable frac/well connection for successful fracturing and well testing. The paper will describe how the intervention tools and practices have varied between the Barik and Amin formations; depending upon rock quality, frac treatment type, drive to maximize operational efficiency and availability of local resources. The differential application of these techniques, that result in measurable under-flush versus in contrast to the typical North American unconventional practice of defined but limited overflush (e.g., pump-down plug-and-perf will be described). Justification for these different approaches in two very different formations will be demonstrated, including supporting evidence of their relative value.
The obstacles that have been faced, overcome and are still ongoing with this campaign highlight the importance of several critical factors: including multi-disciplinary integration and planning, wellbore construction impacts, contractor performance and tool reliability. Although practices for shale and very low permeability sands are well documented, this paper provides a suite of case histories and operational results for horizontal well intervention techniques used in high-pressure and high-temperature sandstones that are in the very specialized transition zone between conventional and unconventional.
Pineda, Wilson (BP) | Wadsworth, Jennifer (BP) | Halverson, Dann (BP) | Mathers, Genevive (BP) | Cedillo, Gerardo (BP) | Maeso, Carlos (Schlumberger) | Maggs, David (Schlumberger) | Watcharophat, Hathairat (Schlumberger) | Xu, Weixin (Wayne) (Schlumberger)
Deepwater depositional environments in the Gulf of Mexico can be very complex. Accurate determination of depositional facies is important in these capital-intensive fields. The most common reservoir facies are laterally extensive sheet sandstones with thin mudrock layers, channel complexes (isolated or amalgamated) and channel-levee complexes (often with poor reservoir communication). Reservoirs are often complicated by steep dips close to salt domes and the presence of potential fluid conduits due to faults or fractures. Borehole images aid in determining the character of the sediments, as well as improve net sand calculations, and illuminate the geology in the near wellbore region both in structure and depositional environment, and to provide valuable geomechanics information for the determination of the stress vector.
A well was recently drilled through one of these deep water sediment sequences in the Gulf of Mexico with an oil-based mud (OBM) system. An extensive acquisition program included a series of logging while drilling (LWD) and wireline images. In addition to the current LWD lower resolution borehole imaging tools, a new LWD dual physics OBM imager was deployed for the first time in this field. Five different types of physics were acquired, including lower-resolution images from nuclear measurements (gamma ray, density and photoelectric) and the high-resolution images from dualphysics OBM imager (DPOI) which is based on resistivity and ultrasonic measurements. Wireline high-resolution OBM resistivity images were also acquired. This paper shows a comparison of images collected with the new DPOI versus traditional LWD images and high-resolution wireline resistivity images.
Comparisons of the types of features observed from the various imaging tools were made, showing how the differences in physics, resolution and time of logging affects the images, as well as the impact these factors can have on subsequent interpretations. Four main categories of features are included in comparisons between the tools: sand-rich sections, consistently dipping mudrocks, chaotic zones and fractures/faults. The different images allow fuller interpretation of the gross sequence. In general, the higher the resolution, the more detailed and confident the interpretation is, particularly where the hole conditions are good. In degraded borehole sections, the LWD acquisition was beneficial for obtaining images as early as possible, when damage was at a minimum. The impact of the differences in the physics depends on the properties and contrasts being imaged. This is observed with fractures - both conductive and resistive examples can be seen on both LWD and wireline images. The ultrasonic images are complementary with both low and high amplitude fractures seen, providing more confidence in the fracture interpretation.
Rabinovich, Michael (BP) | Bergeron, John (BP) | Cedillo, Gerardo (BP) | Mousavi, Maryam (BP) | Pineda, Wilson (BP) | Soza, Eric (BP) | Le, Fei (Baker Hughes, a GE Company) | Maurer, Hans-Martin (Baker Hughes, a GE Company) | Mirto, Ettore (Schlumberger) | Sun, Keli (Schlumberger)
Copyright 2019 held jointly by the Society of Petrophysicists and Well Log Analysts (SPWLA) and the submitting authors. Annual Logging Symposium held in The Woodlands, TX, USA June 17-19, 2019. ABSTRACT Typically, only conventional logging while drilling (LWD) resistivity and gamma ray logs are acquired in overburden sections of deep-water wells. Very important decisions impacting drilling safety and borehole stability must be made based on correct and timely interpretation of these logs. Drilling-induced fractures, faults, and eccentricity effects in large holes drilled with oil-based mud are common reasons for anomalous responses of LWD resistivity tools in overburden sections. These anomalies are often associated with fluid losses and other drilling hazards such as borehole assembly sticking. With the limited number of real-time (RT) measurements even if the optimal minimal set of RT curves is selected, the interpretation of these anomalies is challenging. Drilling-induced fractures can be misinterpreted as eccentricity or even as a permeable zone with resistive invasion in water sands or with a hydrocarbon-bearing layer, which is especially important for proper casing and cementing decisions. Resistivity modelling is an irreplaceable tool that enables us to uniquely identify the cause of each anomaly. Time-lapse measurements also help to recognize and identify the causes of anomalies as borehole conditions change with time. Fractures can become deeper with continued overbalance or healed with lost-circulation material or a reduction of equivalent circulating density. Washouts typically enlarge with time and after reaming. We present several case studies from deep-water wells in the Gulf of Mexico illustrating typical LWD resistivity anomalies in overburden sections. The examples include fault identification and borehole events such as fluid losses, borehole enlargement, and gas-bearing intervals. The challenges of interpreting each anomaly and the necessity of the appropriate LWD resistivity modeling kit are clearly demonstrated. Many of the examples illustrate the advantages of measuring after drilling (MAD pass) logs. INTRODUCTION When drilling overburden sections in deep water wells, the hole diameters are big, open hole sections are long and, typically, the LWD suite is limited to conventional resistivity and gamma ray (GR) logs. Additionally, the limited number of real-time (RT) resistivity curves makes the unique interpretation of resistivity data difficult.
Engineers need to predict the production characteristics from hydraulically fractured wells in tight gas fields. Decline curve analysis (DCA) has been widely used over many years in conventional oil and gas fields. It is often applied to tight gas, but there is uncertainty regarding the period of production data needed for accurate prediction.
In this paper decline curve analysis of simulated production data from models of hydraulically fractured wells is used to to develop improved methods for calibrating decline curve parameters from production data. The well models were constructed using data from the Khazzan field in Oman. The impact of layering, permeability and drainage area on well performance is also investigated. The contribution of each layer to recovery and the mechanisms controlling that contribution is explored.
The investigation shows that increasing the amount of production data used to fit a hyperbolic decline curve does not improve predictions of recovery unless that data comes from many years (20 years for a 1mD reservoir) of production. This is because there is a long period of transient flow in tight gas reservoirs that biases the fitting and results in incorrect predictions of late time performance. Better predictions can be made by estimating the time at which boundary dominated flow is first observed (tb), omitting the preceding transient data and fitting the decline curve to a shorter interval of data starting at tb. For single layer cases, tb can be estimated analytically using the permeability, porosity, compressibility and length scale of the drainage volume associated with the well. Alternatively, tb can be determined from the production data allowing improved prediction of performance from 2-layer reservoirs provided that a) there is high cross-flow or b) there is no cross-flow and the lower permeability layer either does not experience BDF during the field life time or it is established quickly.
Essam, Wael (BP) | Scarborough, Christopher (BP) | Wilson, Nick (BP) | Shimi, Ahmed (BP) | Santos, Helio (Safekick) | Hannam, Jason (Safekick) | Catak, Erdem (Safekick) | Lancaster, Jay (Seadrill) | Gooding, Neil (Seadrill) | Baan, Robert (Seadrill)
BP had long recognized the benefits of MPD, having been using it for years to deliver very challenging wells in Egypt, Trinidad and the North Sea; and it was time to bring these benefits to its GoM operations. Once the company team identified a portfolio of suitable candidate wells to allow the economics of the application to be advantageous, they partnered with Seadrill to provide the MPD service integrated into the West Capricorn drilling rig. This approach builds on synergies within the drilling contractor organization to achieve long term economic, competency, and risk management benefits, resulting from integrating this drilling method on the rig, and eliminating interfaces with 3rd party providers. The paper will discuss how the company and the drilling contractor teams, together with equipment suppliers and training providers, managed the project from initial system design, to installation and commissioning, to the successful delivery of the first well using MPD, at top quartile performance. It will discuss the process for optimizing the design and testing it from a reliability and process safety perspectives; engaging the regulatory authority and the classification society; integrating MPD in the well planning process and developing operational procedures for use on the rig; and delivering a training program for the wider team covering the technical and the human factors aspects to ensure a successful delivery.
Hadiaman, Farid (BP) | Mollayev, Samir (BP) | Huseynzade, Nijat (BP) | Valiyev, Ziya (BP) | Gracia, Jesse (BP) | Galvan Amaya, Jeanine (BP) | Fulks, Jeff (BiSN) | Rahimov, Khalid (Baker Hughes GE) | Pinero, Luis (Baker Hughes GE) | Ruzmetova, Sitora (Baker Hughes GE)
Thru-tubing uphole re-completion is a workover technique aiming to re-complete the existing wellbore by abandoning the lower producing zone and subsequently perforate upper layer. There are various techniques used to abandon the lower zone worldwide. Specific to Caspian Sea development, the abandonment will only be required to set an isolation plug. However, statistically speaking, success ratio of lower zone abandonment, is quite low using current plugs set in different condition of completion. In addition, the risk of deploying balance cement plug also presents significant challenge due to interval limitation between top of the cement and new perforation interval. It is deemed necessary to find a fit-for purpose solution that provides a solution to the Caspian Sea environment plug and abandonment strategy. A new plug technology, metal to metal system, was introduced to provide assurance isolating the lower zone prior to perforating new upper zone. Subsequently, a wireline deployed or pipe (tubing) conveyed perforation is not an attractive solution to thru-tubing up-hole recompletion technique. A new technology to perforate lively is selected from safety and economic point of view for this specific well. The perforation was done in underbalance condition with intelligent coiled tubing. The uphole re-completion (well delivery) performance was more attractive than other conventional uphole re-completion techniques. This paper will elaborate the success of recompletion techniques by deploying multiple new technologies in the Caspian Sea.