Artificial Lift

The Apache-operated Adair San Andres Unit (ASAU) currently employs fifteen capillary string (cap string) equipped producing wells, representing 16% of the active producer count. Apache started converting producing wells to cap strings in 2016.  This idea was introduced to Apache at the 2012 CO2 Conference in Midland and later reinforced during a field tour of Whiting’s North Ward Estes CO2 flood in 2015.  The chief benefit using a cap string is production stability.  A review of these installations 

Dog Leg Severity (DLS) had been used for many decades as recommendations to try to drill oil and gas wells and provide "trouble free" operating conditions. Many of these recommendations were historically based on vertical, shallow (<5000 ft.) deep wells. But as wells continued to be drilled deeper, the recommendations were still applied. With the current drilling and operating practices of deviated and/or horizontal wells, these recommendations may no longer be applicable.

One of the largest lease operating expenses is electrical cost. Only a small portion of electrical cost is value-added conversion of electricity to fluid lifting power. The rest is lost to downhole friction, fluid flow friction, pumping unit, and electrical to mechanical power conversion inefficiencies.  Overall “line to fluid” system efficiency will typically range from 20% to 40%. Some cases will be as low as 10%.

The common surface chemical applications cannot reach or have low efficiency due to high fluid levels. This paper Introduces a new chemical technology for all types of artificial lift systems that guarantees an efficient downhole treatment at the entry point and summarizes the applications of this revolutionary method established to deliver chemical combinations by microencapsulating the compounds and packaging the completed formulation in a chemical screen that is placed at the bottom of the tubing (BHA) below any type of artificial lift systems.

High gas-liquid formation ratios appear as the fluid level decreases and as a result significant decreases in pumping efficiency are seen in the ESPs. This problem force frequent shutdowns in the pump because the gas is incapable of adequately cooling the motor and this forces the companies to maintain high fluid levels to avoid the formation of free gas at the pump intake, which increases the PIP and limits the production of fluid. A new and innovative downhole gas separator has been introduced in recent applications to treat gas slug’s problems.

Wells with high depletion rate present high free gas at pump intake conditions. In all cases, the production of fluid with a high gas-liquid ratio leads to an inefficient performance of the rod pump systems. The initial solution to this problem is the installation of poor boy gas separators which capacity of gas separation is reduced and do not provide a high-performance solution.  Packer type gas separators are the most efficient downhole separators in the market, however, they usually have some operational limitations.

As fluctuations in oil price continue, the industry has changed and is demanding improvements from each method of artificial lift. Required flow rates are increasing due to the longer laterals of new horizontal wells being added to inventory. Rod Lift is not immune and is being asked to enter the artificial lift cycle earlier and support the pumping of wellbores with added complexities due to geometries and/or production demands. The fiber reinforced plastic (fiberglass, FSR) rod continues to meet the ever-increasing demand and complexities.

In 2017 and 2018 Oxy EOR conducted a series of RCFA schools. As part of these schools, information was gathered on the range of equipment replacement for failure types. In 2018, a cross functional team of experienced stakeholders vetted this information and compiled a list of equipment replacement guidelines. This paper will share these guidelines. 

Typically, the Petroleum Industry maintains operational ideas that were developed years ago.  These operational ideas may still have merit, but some improvements should be considered.  Sucker rod guides are an example of such practices.  Most production companies continue to use rod guide material that was introduced at the conception of the recognition of the need for sucker rod guides.  This presentation will give information of new materials and new application ideas for sucker rods guides. 

In 2014 Oxy EOR had lost confidence in the accuracy of Fluid Levels in CO2 wells and was not shooting them. Echometer and Oxy collaborated to identify the root cause of the fluid level inaccuracy and resolve the issue through improved procedures and educating personnel. Today trusted fluid level information adds value by improved operational decision making.