Mature belongings by definition are oil and gasoline fields which have been producing for upwards of twenty-five years. Thus, the Niger Delta Basin is taken into account a mature oil and gasoline producing area, one with an abundance of extremely prolific hydrocarbon dicoveries which incorporates a number of undeveloped prospects.
Mature belongings current a definite mixture of challenges and alternatives, particularly at a time when a wave of bold indigenous operators—grappling with widespread manufacturing decline—are projected to contribute round 60% of the nation’s output.
Maturity within the Niger Delta signifies many years of sustained exploration and manufacturing exercise. With the area at the moment accounting for as much as 90% of Nigeria’s oil output and no new main fields anticipated to return onstream earlier than the last decade ends, the urgency to maximise worth from these mature belongings couldn’t be overstated. Software of know-how underpins the power to breathe new life into mature fields and speed up manufacturing of low price barrels from current wells with proximity to current infrastructure.
Nigeria urgently wants to revive its manufacturing baseline of two million barrels of oil per day to assist ease persistent macroeconomic pressures and for its power safety. Within the brief to medium time period, realizing this goal will largely rely on how effectively impartial operators, in three way partnership with NNPC, can drill in-fill wells, reactivate dormant ones and optimize manufacturing from underperforming belongings.
Driving Manufacturing Development By means of Modern Know-how
A proliferation of inactive wells dot the Niger Delta panorama—better than 2000 in whole with about 600 within the management of Seplat and Renaisance—representing better than 150K locked in oil barrels. This presents a pool of belongings that may solely be unlocked by means of progressive, cost-effective and know-how pushed improvement methods.
In what’s greatest thought of a technological paradigm shift and one of many main hallmarks of innovation within the oil and gasoline business, Horizontal drilling, which basically will increase wellbore publicity throughout the lateral extent of the reservoir started to achieve vast adoption across the mid-nineties and stand out until at the present time for its hydrocarbon restoration and manufacturing enhancement potential. Horizontal drilling is now utilized increasingly more to reactivate and rejuvenate fields which might be close to or have reached their financial restrict.
The upside potential for horizontal drilling is very large if utilized correctly and in the appropriate discipline. Exposing extra reservoir rock to the wellbore minimizes strain drawdown.
Diminished strain drawdown particularly in low permeability reservoir of < 1 Darcy, in thin-thickness excessive permeability zones, or in vertical fractures, horizontal wells stabilize reservoir dynamics, minimizing dangers like water coning or gasoline cusping that ceaselessly compromise vertical wells (Joshi 1991). The result's enhanced restoration charges and higher reservoir stability.
Horizontal drilling minimizes the necessity for a number of wells by draining bigger reservoir areas with a single nicely. This reduces capital expenditure and operational prices whereas enhancing the sphere’s total economics—a main driver for upstream enterprise operations.
Determine 1: Manufacturing Comparability—Horizontal Nicely vs. Vertical Wells in Excessive GOR Oilfield In excessive gas-oil ratio (GOR) oilfields, horizontal wells considerably outperform vertical wells, producing greater volumes of oil (left) and smaller quantities of gasoline (proper). This information from Canada’s Devonian Rainbow Reef Reservoir demonstrates how re-entry horizontal sidetracking enabled operators to extract oil effectively with out an extreme gasoline reduce. (Supply: McIntyre et.al. 1994).
Zeroing in on the Proper Know-how
Horizontal wells are sometimes grouped in 4 classes: Lengthy radius, Medium radius, Brief radius and the Extremely brief radius – in keeping with radius of curvature transversed by the nicely bore because it passes from the vertical to the horizontal.
The Extremely Brief Radius (USR) re-entry and completion system is a quickly deployable and cost-effective know-how that expands using horizontal drilling in current wells. Objective-built to entry bypassed reserves, improve manufacturing from marginal wells, revive shut-in wells, and scale back water reduce, USR know-how unlocks asset worth in methods typical horizontal strategies can’t.
Extremely brief radius (USR) gear can be utilized to re-enter a vertical nicely and drill a horizontal drain-hole with shortest potential radius of curvature (8-17m)* the place the TVD consumed by curve is lower than 17m and restricted to the pay zone by conserving excessive construct up fee (near 250° per 30m) and lateral departure of about 150m in size.
USR horizontal drilling is the popular possibility in heterogeneous, low permeability, skinny layered, semi-depleted, naturally fractured reservoirs or when coning of water / gasoline is predicted to intrude with full restoration. Utilizing USR horizontal drain holes, oil will be produced at low draw-down pressures conserving away water coning so long as potential and with out decreasing manufacturing charges.
Determine 2: Comparative Evaluation of USR Sidetracking vs. Massive Radius New Nicely
This diagram comparesUSR sidetracking (blue) andLarge Radius (LR) new nicely (purple) in a center east nation, illustrating their distinct reservoir entry methods.
USR trajectory stays solely throughout the Shugaba Reservoir, effectively draining oil inside an 800-foot radius whereas avoidingNazir Umur shale by sidetracking on the reservoir’s prime. This eliminates the necessity foradditional casing strings, not like LR wells, which encounter shale alongside their prolonged curve part.
The comparability highlightsUSR’s cost-efficiency, exhibiting how shorter curve intervalsreduce drilling complexity, optimize reservoir publicity, and decrease casing necessities—key components in bettering nicely economics. Whereas LR wells present prolonged lateral attain, USR sidetracks unlock bypassed reserves close to current wellbores, providing a complementary improvement technique.
Outcomes from seven USR sidetracks within the documented case showIP will increase of 1.9–5.5x over the unique vertical wells, together with one nicely bettering from0 to 227 BOPD and one other with a0.3x improve.
With a wide range of purposes in low producing wells, tightly spaced fields, wells with water coning, channel sands with surrounding shale and exploitation of attic oil, drilling low-cost horizontal wells from current vertical, or deviated wellbores, utilizing USR drilling applied sciences, will considerably enhance oil restoration and economics of at the moment producing oilfields in Nigeriaand develop reserves.
Along with vital price financial savings achievable (Comparable with the price of a standard intervention and 40 – 50% beneath the price of a brand new nicely), the appliance of the distinctive USRD intervention know-how brings ahead the window of alternative to unlock as much as 200K BOPD in eighteen (18) months – similar to elevated nicely productiveness issue vary of 1.8 – 2.5.
Determine 3: Nigeria’s Manufacturing Ramp-Up Forecast (Notional)
USR Affords the Following Benefits Over Typical Horizontal Drilling Techniques:
USR drilling allows kick-off level to be at a depth very close to, or in quite a few instances, inside the target hydrocarbon zone itself. This is because of its extremely brief ROC of 7-17m as in comparison with over 300m within the above chart. Downhole Pumps or Gasoline Elevate Valves, for example, will be positioned at or close to the highest of the pay zone to maximise manufacturing effectivity and prolong the productive lifetime of the nicely as a consequence of decrease abandonment pressures. USR drilling allows the touchdown of the nicely bore at a distance very close to to unique nicely bore in case of re-entry drilling from current nicely i.e. Sidetrack, at 8-9m from unique nicely bore as in comparison with a a lot better distance of over 300m. As a consequence of such low ROC, touchdown in skinny targets close to the prevailing nicely bore will be extra simply achieved. It could actually get rid of the necessity for costly electrical wireline logging as a consequence of its extremely brief vertical part and touchdown level from the unique nicely bore from which geology, manufacturing and reservoir information are available. Tighter curves enable horizontal sections to be initiated nearer the prevailing nicely bore with identified information. Usually the target pay zone is missed as a result of presence of lenses or minor faults which aren’t recognized by seismic or different discipline information. A extra exact placement of the horizontal nicely bore permits for a extra environment friendly improvement of carefully spaced fields. Permits precision placement of a horizontal part throughout the target hydrocarbon zone, at a really shut distance to the kick-off level. The drilled distance from kickoff depth to finish of curve depth is far shorter than conventionally drilled wells. USR curves require lower than 20m of drilled gap versus greater than 500m. Shorter curves primarily based on native benchmarks saves hundreds of thousands of {dollars} in drilling prices. Generally the place reservoir thickness permits, kickoff factors will be set beneath drawback zones with water, gasoline caps or shales that may be tough to drill as a consequence of gap stability. The complete curve and lateral will be drilled within the producing formation and beneath cap rock. Wellbores are slim gap which permits for inexpensive Workover Sort Rigs or Hydraulic Workover Hoists, smaller pumps and circulating programs for use. A number of laterals will be drilled in opposing instructions or in the identical path, touchdown on the similar true vertical depth (“TVD”) or at various TVD’s. A number of Laterals will be Drilled From a Single Nicely-bore;
In conclusion, USR Drilling affords Nigerian operators a viable and cost-effective various know-how that’s particularly nicely fitted to use as a reentry software within the “Brownfields” of the Niger Delta. Adopting the USR Drilling know-how broadly in Nigerian upstream operations might measurably enhance key operational metrics – Unit Working prices and Unit Improvement Prices – according to current authorities’s price restructuring aspirations.
References
Chi Zhang, Wei Zhou, Ningbo Cheng. 2016. “Overview of Rotary Steerable System and Its Management Strategies.” IEEE Worldwide Convention on Mechatronics and Automation. Harbin, China: IEEE. 1559-1565. Hill, D, E Neme, and C Ehlig-Economides. 1996. “Reentry Drilling Provides New Life to Growing older Fields.” Oilfield Evaluation 4-17 Hou, Cougar. 2010. Incremental Oil Restoration Applied sciences For Mature Fields. Jereh Group Inner Presentation. Ingold, Charles. 2007. “Brief-Radius Drilling: A Decade of Improvement.” Drilling Contractor 74-76
Joshi, Sada D. 1991. Horizontal Nicely Know-how. Tulsa, Oklahoma: PennWell Publishing Firm.
Kesonpat, Okay, and E Berkheimer. 2005. “Rima-8 H5 USR Re-Entry Sidetrack: Failure Evaluation of ACPT Composite Drill Pipe Utilizing Drilling Stress Simulations and Beneficial Wayforward.” PDO Mission Report, Nicely Engineering, Petroleum Improvement Oman, Muscat.
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