Case Histories: Haynesville, Fayetteville, and Bakken Shales

Momentive conducted extensive research on well production in several shale plays in North America. The case histories that resulted from the studies clearly correlate the use of resin coated proppants to increased well production.

Haynesville Shale

The Haynesville Shale is one of the largest producing shale plays in the US. The play is located primarily in northwest Louisiana and runs into east Texas and southern Arkansas.

Wells in this formation have typical measured depths of 14,000 to 18,000 ft. True vertical depths (TVD) in the Haynesville Shale typically range from 10,000 to 13,000 ft with 4,000 ft laterals or longer. Closure stress ranges from 9,000 to 12,000 psi and bottom-hole temperatures reach 325°F or more. This makes the Haynesville one of the deepest shale plays in North America with HPHT (high pressure, high temperature) well conditions.

Well Production Results Comparison of Prime Plus vs. Lightweight Ceramic

The Haynesville Shale study reviewed the production results of 16 wells. All the fracture treatments were completed on wells in DeSoto Parish, Louisiana. The wells had similar characteristics, completion techniques, frac stages, and proppant volumes. The proppants used were Prime Plus™ 40/70 which is a curable resin coated sand (CRCS) and a 40/80 mesh lightweight ceramic (LWC).

As you can see in the chart (click to enlarge), the results showed that the average 10 month cumulative gas production for the Prime Plus wells was 1.98 Bcf, while the LWC production was only 1.45 Bcf. The wells that utilized Prime Plus proppant provided 37% higher production than the LWC wells.

The differences in well production seen in the study were due to Prime Plus' curable resin, which provides resistance to fines caused by crushing, pack cyclic stress, proppant embedment, and downhole proppant scaling.

Fayetteville Shale

The Fayetteville Shale is part of the Arkoma Basin. It is a gas shale that is located in north-central Arkansas.

Well depths vary broadly from approximately 1,500 to 7,000 ft. Lateral lengths typically run between 3,000 to 4,000 ft. Bottom-hole temperatures range from 100 to 150°F with an average fracture closure stress of 6,000 psi (FG = 1.1 psi/ft) or less. Wells flow at an initial production (IP) averaging one to three million cubic ft (MMcf) per day and decline at a lesser rate than in other shale plays.

Most of the wells are horizontals with an average of six to ten frac stages. Frac treatments generally are slickwater using 300,000 to 400,000 lbm of proppant, with concentrations stepping from 0.1 up to 2.2 lbm/gal. Pump rates range from 80 to 100 bbl/min.

Well Production Results Comparison of ValuBond vs. Uncoated Frac Sand

Fracture treatments on 17 wells were compared in White County, Arkansas. All the wells had similar characteristics and completion techniques. Ten of the wells utilized 100% 40/70 uncoated frac sand (UFS) while seven wells had 10% tail-ins using a ValuBond™ 40/70. The average 12 month cumulative gas production for the ValuBond wells was 20% higher than the UFS wells. This resulted in a $237,000 increase in profit per well (based on April 2011 gas rates).

The incremental ValuBond proppant cost was recovered within the first two months. Reduced proppant flowback and less well downtime for cleanouts were also reported. ValuBond wells are producing more gas due to less proppant fines and less proppant flowback compared to UFS wells.

Bakken Shale

The Bakken is an oil shale in the center of the Williston Basin occupying roughly 200,000 square miles of North Dakota, Montana, and Saskatchewan, Canada. The Bakken is divided into three sections; the upper and the lower separated by the middle sandy shale.

The majority of the wells drilled in the United States Bakken are horizontal 8,500 to 10,000 ft laterals at vertical depths up to 10,000 ft. Closure stresses generally range up to 9,500 psi depending on depth and location.

 

 

Well Production Results Comparison of SB Prime vs. Uncoated Frac Sand

A study was conducted comparing the productivity of 13 Bakken wells in Dunn County, North Dakota fractured with SB Prime™ and UFS. The test group consisted of five wells using 20/40 SB Prime and the remaining eight wells used 20/40 UFS. All wells had similar vertical depths, lateral lengths, and similar completion techniques. The average nine month cumulative oil production for the SB Prime wells was 40% higher than the UFS wells.

SB Prime CRCS wells are making more oil due to less proppant fines and less proppant embedment compared to UFS wells.

Conclusion

As the production results and laboratory tests prove, the use of Momentive's curable resin coated proppants drastically increased the production and profitability of the wells studied compared to other types of proppants. For more information, you can visit waterfrac.com or download our SPE 135502 technical paper.