Development and Efficiency Testing of Sucker Rod Pump Downhole Desanders

Abstract

Summary Tense economic situations push the demand for low-cost oil production, which is especially challenging for production in mature oil fields. Therefore, an increase in the meantime between failure and the limitation of equipment damage is essential. A significant number of wells in mature fields are suffering under sand by-production. The objective of this paper is to show the development process and the testing procedure of an in-house-built, effective downhole desander for sucker rod pumps on the basis of a sophisticated analytical design model. In weak reservoir zones, often the strategy to prevent equipment damage due to sand by-production is the sand exclusion method using a gravel pack. Nevertheless, a certain amount of small sand grains still enter the wellbore and may damage the sucker rod pumping system over time. In early 2018, various types and sizes of downhole desander configurations were tested at the pump testing facility (PTF) at the University of Leoben (Montanuniversitaet Leoben). In a period of about 4 months, testing took place under near field conditions to find the optimum and most efficient design. The design optimization was focused on the geometry of the swirl vanes and the sand separation distance at the sucker rod pump intake. An analytical model provided the basis for geometric optimization. Concurrently, field tests of the in-house downhole desander were performed in the Vienna Basin that confirmed the findings of the tests at the PTF. The test results have shown that the downhole desander design and the pumping speed are the most influencing parameters on sand separation efficiency. Poor design in combination with a wrongly selected pumping speed can reduce the sand separation efficiency to lower than 50%, while if all parameters are chosen correctly, the sand separation efficiency can be 95% or higher. The grain size distribution is the additional parameter that enables a decision and ranks the performance. The sensitivity analysis, performed for several downhole desander types, has shown the high dependency of the sand separation efficiency on the major desander design parameters. Proper selection of the components and operating parameters will contribute to an increase in the meantime between failures. This paper will present the testing configurations, the development of the high-efficiency in-house downhole desander, and the sensitivity analysis performed on the design.

A comprehensive review of sucker rod pumps’ components, diagnostics, mathematical models, and common failures and mitigations

“…Figure 15 shows an example of a worn-down plunger surface valve and a ball seat valve. Proper operational and design procedures can reduce the risk of pin and coupling wear (Langbauer et al 2020).…”

“…This can cause plugging problems that are very difficult to mitigate. The three main methods by which sand production in sucker rod can be mitigated include (Langbauer et al 2020):…”

Sucker rod pump downhole dynamometer card determination based on a novel finite element method

“…Share of the significant artificial lift systems based on installed units [3] Since the early days of sucker rod pumping, engineers and scientists are looking to predict and analyze the sucker rod pump. To mention an excerpt of work performed in the past acoustic signals of pumping systems have been used to detect the operation condition [4], the evaluation of equipment like plunger slippage models [5] and downhole desanders [6] has been performed in the laboratory and in the field. Extensive testing capacities have been constructed at the university to push the advances in sucker rod pumping [7], [8].…”

A holistic review on hydraulic fracturing stimulation laboratory experiments and their transition to enhanced geothermal system field research and operations

“…Fractured formations tend to produce fines along with the reservoir fluid due to the damages initiated during hydraulic fracturing. Serious research was performed in the past to mitigate problems of artificial lift systems, associated with fines production [2], [3], [4] [5], and new technologies [6], [7] and laboratory testing capacities [8], [9] have been introduced. Over the past decade, much time and effort have been dedicated to better understand the key factors that drive an EGS fracturing project towards success.…”