echnological advancements to produce hydrocarbon fluids from the reservoir to the surface has generally been most prevalent in directional drilling. As wells come online, their IP is typically supported by electric submersible pumps or gas-lift technologies, which are relatively unaffected by wellbore geometry. As production rates decline, wells are converted to reciprocating rod lift, understood as the most economical form of producing fluids. Modern, unconventional, directional deviated and horizontal wells bring challenges to industry. The drilling department’s decision-making most often does not have the flexibility to consider lifelong production complications due to wellbore path and design. High deviation, doglegs or changes in direction lead to an increase in failure frequency when on reciprocating rod lift. It is imperative for sucker rod pumping to remain economical and reliable in modern wellbores.
A new manufacturing process led by product design has been commercialized for sucker rod pumping. Material science is paramount to the utilization of this new technology. Black Mamba Rod Lift’s sucker rod stabilizer is marketed as end-to-end sucker rod control for well operators. The Black Mamba, an over-molded helical centralizer, is available for use with traditional steel sucker rods and is rapidly finding its way through the marketplace.
Traditional deviated vertical wells feature doglegs and troublesome geometry farther down the wellbore. These areas are commonly addressed with consumable plastic 4-fin sucker rod guides or centralizers. The guides and centralizers prevent steel-on-steel wear between the rodstring and production tubing.
Deep unconventional horizontal wells are drilled efficiently by using multiwell pads; this drilling practice causes significant deviation, translating to high side loads when designing for reciprocating rod lift applications. The axial load on the rodstring is greater farther up the rodstring (rod weight plus fluid load). When the rodstring makes contact with the tubing, this axial load is transferred by way of side forces causing rod-on-tubing wear. High side loads lead to holes-in-tubing and sucker rod parts, failures commonly observed throughout industry.
echnological advancements to produce hydrocarbon fluids from the reservoir to the surface has generally been most prevalent in directional drilling. As wells come online, their IP is typically supported by electric submersible pumps or gas-lift technologies, which are relatively unaffected by wellbore geometry. As production rates decline, wells are converted to reciprocating rod lift, understood as the most economical form of producing fluids. Modern, unconventional, directional deviated and horizontal wells bring challenges to industry. The drilling department’s decision-making most often does not have the flexibility to consider lifelong production complications due to wellbore path and design. High deviation, doglegs or changes in direction lead to an increase in failure frequency when on reciprocating rod lift. It is imperative for sucker rod pumping to remain economical and reliable in modern wellbores.
A new manufacturing process led by product design has been commercialized for sucker rod pumping. Material science is paramount to the utilization of this new technology. Black Mamba Rod Lift’s sucker rod stabilizer is marketed as end-to-end sucker rod control for well operators. The Black Mamba, an over-molded helical centralizer, is available for use with traditional steel sucker rods and is rapidly finding its way through the marketplace.
Traditional deviated vertical wells feature doglegs and troublesome geometry farther down the wellbore. These areas are commonly addressed with consumable plastic 4-fin sucker rod guides or centralizers. The guides and centralizers prevent steel-on-steel wear between the rodstring and production tubing.
Deep unconventional horizontal wells are drilled efficiently by using multiwell pads; this drilling practice causes significant deviation, translating to high side loads when designing for reciprocating rod lift applications. The axial load on the rodstring is greater farther up the rodstring (rod weight plus fluid load). When the rodstring makes contact with the tubing, this axial load is transferred by way of side forces causing rod-on-tubing wear. High side loads lead to holes-in-tubing and sucker rod parts, failures commonly observed throughout industry.
In this case, operators may opt for a “high-clearance” pump, which allows the solids to pass and be produced. With increased clearances, downhole pump efficiency is reduced. To counter this, operators will set the surface pumping unit to operate at an increased rate. An increase in acceleration and velocity of the rodstring then exacerbates all potential issues of compression, side load and tagging, which leads to an increase in failure rates as the system is cycling more often at higher velocity and with higher kinetic energy in a given amount of time.
In all instances of the above, sucker rod flex, compression and/or buckling cause drastic increases in stress along the sucker rod, sometimes far greater than peak tensile stresses predictive software computes during the upstroke when fluid is lifted.
Compression can cause buckling or instability in the sucker rodstring, creating high stresses found at rigid areas along the sucker rod body. These high stresses create micro-fractures in the surface of the steel rod that propagate and lead to a guaranteed eventual rod part.
For a slick, unguided sucker rod, bending moments and micro-fractures occur at the transition point from the forged upset down to the primary sucker rod body diameter. For guided sucker rods, bending moments and common rod failure locations occur at the edges of sucker rod guides where the rod is held rigid and centered in the tubing.
A drastic increase in sucker rod life can occur if these instances of compression are controlled and accommodated. Compression is not necessarily problematic when sucker rod instability is alleviated, preventing the bending moments and high-tensile stresses during compression instances.
When compression occurs, the rod is held co-axially in alignment with the production tubing. Bending moments are eliminated as the sucker rod can flex and move, yet the rod is still centralized when in the rodstring is operating as intended in tension. If compression exceeds the critical buckling load of The Black Mamba two per, three per or four guides per rod configuration, it is best to utilize Black Mamba Rod Lift’s fully guided sucker rod molded as seven guides per rod. The engineering and reinforcement of the rod and centralizer assembly increases the sucker rod’s critical buckling load (the peak compressive load before instability, e.g., buckling occurs) beyond what is possible in a rodstring design. Peak compressive load potential is mostly equal to the weight of the rodstring above the sucker rod in question.
COO with Black Mamba Rod Lift
Operators can pump the curve with confidence, setting the downhole pump beyond the kickoff point allowing greater pump fillage and reduced pump-off time. Utilized as a replacement for traditional legacy sucker rod guides, The Black Mamba can be substituted for traditional guided sucker rods and eliminate the need for heavy sinker bars and costly stabilizer bars, providing superior sucker rodstring protection and control at a reduced cost.