The objective of this work is to demonstrate that the choice of the conveyance method for Production Logging operations is key in horizontal wells, as it affects the flow dynamics and changes the well inflow performance compared to undisturbed flowing conditions. A case study is presented, showing that critical decisions to develop a field (or not) may have been wrongly influenced by Production Logging results, if the effects of the conveyance on the inflow distribution were not correctly understood.
Synthetic production logs and flowing pressure distributions along the horizontal section were computed, and sensitivities on conveyance method diameter (coiled tubing, tractor and cable), pipe diameter, well length and reservoir properties were also conducted. These results were compared with the normal well flowing conditions to establish the representativeness of the PL measurements. A method for simulating the undisturbed production profile is presented, which uses the results of a Multirate Production Logging and recomputed flowing pressures using nodal analysis.
The presence of the conveyance method alters the well's inflow performance and zonal contributions, due to the modifications of the flow geometry and additional frictional pressure drop. The bottomhole flowing pressure is disturbed, with lower pressures around the heel and higher towards the toe. The drawdown along the horizontal gets modified, acting as a preferential choke for production coming from the toe and increasing the driving force for production from the heel. The severity of the drawdown unbalance is a function of the induced frictional pressure, given by the pipe and conveyance diameter, well length, flow rates, etc. The simulations and sensitivities presented in this paper help to understand how significant the PL measurements are, and when these results become misleading. The case study supports these findings, where the pressure disturbance induced by the conveyance changed the flow distribution dramatically, wrongly indicating than an area of the field was relatively depleted compared to the zone around the heel. The lack of understanding of the impact of the conveyance method can lead to poor developmental decisions.
In a collaborative project, the possibility of measuring fluid levels in a wellbore by use of distributed optical pressure gauges was conceived, prototyped, field-trialed, and further developed to a point of widespread commercialization. The treatment in a deepwater, frac-packed well with fiber-optic-equipped coiled tubing (CT) and a rotating, hydraulic high-pressure jetting tool achieved successful stimulation of a 500-ft-long frac-packed zone after several previous failures using different techniques. In the past decade, fiber-optic -based sensing has opened up opportunities for in-well reservoir surveillance in the oil and gas industry. In this paper, the authors present a recent example of single-phase-flow profiling with distributed acoustic sensing.
Underbalanced coiled tubing drilling has continually advanced since the first trials in the 1990s but remains a relatively niche drilling technology. With UBCTD projects set to start in many countries next year, this technology may be seeing a turning point. Considering most of the rigs deal with human-machine interface systems, the role of human factors is at the heart of any successful operation. Eye-tracking technology can be useful in real-time operation centers where ocular movement data can improve the professionals’ performance. For 60% of Sub-Saharan Africa and South Asia, by cultivated land area, an acute challenge is access to water.
CCUS is an interdisciplinary research field and its broad scope means that CCUS offers numerous opportunities for science and engineering graduates, including petroleum engineers. Underbalanced coiled tubing drilling has continually advanced since the first trials in the 1990s but remains a relatively niche drilling technology. With UBCTD projects set to start in many countries next year, this technology may be seeing a turning point.
This paper covers the staged field-development methodology, including analysis and evaluation of various development concepts, that enabled the company to optimize both completion design and artificial-lift selection, reducing downtime and lowering operating costs by nearly 50%. Completion engineers feel pressure to maximize production per acre and minimize the downsides of fracturing in tight spaces. Terry Palisch, talks about promoting knowledge sharing as part of JPT’s tech director report. Seismic stimulation, achievable with the implementation of a single tool, requires significantly lower investments than gas, thermal, and chemical injection methods, with minimal environmental impact. This paper describes an experimental study with a new propellant and aims to understand the pattern of fracture creation with these propellants.
An oil and gas startup has attracted the business with a major operator thanks to its ability to forecast whether production-enhancing chemicals will work as advertised. The evolution of horizontal drilling and multistage completions has changed matrix stimulation from the “more acid, better result” belief to effective lateral distribution and deeper penetration with less acid. Researchers at the University of Calgary have developed a solid pellet that can transport bitumen and heavy oil by railcar instead of pipelines. With multistage operations becoming the industry norm, operators need easily deployable diversion technologies that will protect previously stimulated perforations and enable addition of new ones. This paper reviews several aspects of the use of in-stage diversion.
This paper describes a new approach to evaluating the effectiveness of the rotary-steerable-system (RSS) steering mechanism on wellbore tortuosity in horizontal wells. This paper demonstrates a work flow to determine optimal lateral lengths and trajectories in the Midland Basin by studying the effect of the lateral length and trajectory on well production. With the arrival and development of rotary steerable systems in the late 1990s, the industry thought that drilling a perfectly smooth and controlled trajectory would not be an issue. Range Resources' drilling head talks about how the company went from drilling the shortest laterals in the Marcellus to the longest and why. The Apollonia tight-gas chalk play is located in the Abu Gharadig Basin in the Western Desert of Egypt.
This paper describes a novel method of chemical dosage based on time-resolved fluorescence (TRF) that allows a simple, accurate, and efficient quantification of chemicals below parts-per-million ranges, even for double (scale/scale, scale/corrosion) quantification. A study done to find the root cause of coiled tubing string failures in Montney indicated microbial-induced corrosion, leading the CT service provider to create a biocide treatment program. Rigless coiled-tubing-unit (CTU) interventions can be effective in returning to production wells that have lost electrical-submersible-pump (ESP) efficiency because of organic, inorganic, or mixed scale deposits. Sour gas is being produced from a number of carbon-steel-completed wells in the US, Canada, France, and Saudi Arabia. This work introduces sodium gluconate as an efficient and environmentally friendly iron-chelating agent.